Control Of Enzymatic Peracid Generation

ABSTRACT

A process is provided for producing target concentrations of peroxycarboxylic acids from carboxylic acid esters. More specifically, carboxylic acid esters are reacted with an inorganic peroxide, such as hydrogen peroxide, in the presence of an enzyme catalyst having perhydrolysis activity under conditions where control of reaction pH by selection of buffer concentration and concentration of perhydrolase and reactants produces a targeted concentration of peroxycarboxylic acids. The present perhydrolase catalysts are classified as members of the carbohydrate esterase family 7 (CE-7) based on the conserved structural features. Further, disinfectant formulations comprising the peracids produced by the processes described herein are provided, as are corresponding methods of use.

This application claims the benefit of U.S. Provisional PatentApplication No. 61/088673, filed Aug. 13, 2008 and U.S. ProvisionalPatent Application No. 61/102520, filed Oct. 3, 2008, both of which areincorporated by reference herein in their entireties.

FIELD OF THE INVENTION

This invention relates to the field of peracid biosynthesis and in situenzyme catalysis. Specifically, a process is provided to control theproduction of peracids generated by the perhydrolysis activity ofenzymes identified structurally as belonging to the CE-7 family ofcarbohydrate esterases, including cephalosporin acetyl hydrolases (CAHs;E.C. 3.1.1.41) and acetyl xylan esterases (AXEs; E.C. 3.1.1.72). Theenzymatic process produces percarboxylic acids from carboxylic acidester substrates. Elucidation of the specific activity versus pH profileof the reaction allows control of the reaction by varying parametersincluding buffer concentration and pH. Disinfectant formulationscomprising the peracids produced by the processes described herein areprovided.

BACKGROUND OF THE INVENTION

Peracid compositions have been reported to be effective antimicrobialagents. Methods to clean, disinfect, and/or sanitize hard surfaces, meatproducts, living plant tissues, and medical devices against undesirablemicrobial growth have been described (U.S. Pat. No. 6,545,047; U.S. Pat.No. 6,183,807; U.S. Pat. No. 6,518,307; U.S. patent applicationpublication 20030026846; and U.S. Pat. No. 5,683,724). Peracids havealso been reported to be useful in preparing bleaching compositions forlaundry detergent applications (U.S. Pat. No. 3,974,082; U.S. patent5,296,161; and U.S. Pat. No. 5,364,554).

Peracids can be prepared by the chemical reaction of a carboxylic acidand hydrogen peroxide (see Organic Peroxides, Daniel Swern, ed., Vol. 1,pp 313-516; Wiley Interscience, New York, 1971). The reaction is usuallycatalyzed by a strong inorganic acid, such as concentrated sulfuricacid. The reaction of hydrogen peroxide with a carboxylic acid is anequilibrium reaction, and the production of peracid is favored by theuse of an excess concentration of peroxide and/or carboxylic acid, or bythe removal of water.

Enzyme catalysts can also catalyze the rapid production of peracid atthe time of use and/or application, avoiding the need for storage ofperacid solutions, which may cause peracid concentration to decreaseover time. The high concentrations of carboxylic acids typically used toproduce peracid via the direct chemical reaction with hydrogen peroxideare not required for enzymatic production of peracid, where theenzyme-catalyzed reaction can use a carboxylic acid ester as substrateat a much lower concentration than is typically used in the chemicalreaction. The enzyme-catalyzed reaction can be performed across a broadrange of pH, depending on enzyme activity and stability at a given pH,and on the substrate specificity for perhydrolysis at a given pH.

Esterases, lipases and some proteases have the ability to catalyze thehydrolysis of alkyl esters to produce the corresponding carboxylic acids(Formula 1):

$\begin{matrix}{{{R_{1}{{COO}R}_{2}} + {H_{2}O}}\overset{\underset{protease}{{Lipase},{esterase},{or}}}{->}{{R_{1}{COOH}} + {{{HO}R}_{2}.}}} & {{Formula}\mspace{14mu} 1}\end{matrix}$

Some esterases, lipases, and proteases also exhibit perhydrolysisactivity, catalyzing the synthesis of peracids from alkyl esters(Formula 2):

$\begin{matrix}{{{R_{1}{{COO}R}_{2}} + {H_{2}O_{2}}}\overset{\underset{protease}{{Lipase},{esterase},{or}}}{->}{{R_{1}{COOOH}} + {{{HO}R}_{2}.}}} & {{Formula}\mspace{14mu} 2}\end{matrix}$

The CE-7 class of carbohydrate esterases has been found to have highlyspecific activity for perhydrolysis of esters, particularly acetylesters of alcohols, diols and glycerols. U.S. patent application Ser.Nos. 11/638,635; 11/743,354; 11/943,872; and 12/143,375 to DiCosimo etal disclose enzymes structurally classified as members of the CE-7family of carbohydrate esterases (e.g., cephalosporin C deacetylases[CAHs] and acetyl xylan esterases [AXEs]) that are characterized bysignificant perhydrolysis activity for converting carboxylic acid esters(in the presence of a suitable source of peroxygen, such as hydrogenperoxide) into peroxycarboxylic acids at concentrations sufficient foruse as a disinfectant and/or a bleaching agent. Under certain reactionconditions, CE-7 esterases can catalyze the production of concentrationsof peracid at least as high as 4000-5000 ppm in 1 min and up to at least9000 ppm in 5 min to 30 min (U.S. patent application Ser. No. 12/143,375to DiCosimo et al). Peroxycarboxylic acids can be corrosive to certainmetal surfaces, however, so it may be desirable to limit the totalamount of peracid produced during the reaction to prevent or minimizethe corrosive effect of the resulting solution. For example,applications that require production of no more than 200 ppm to 1000 ppmof peracid in 1 minute often employ reaction conditions that yield afinal concentration of peracid well above these limits. In anapplication for in situ generation of peracid for disinfection of hardsurfaces, it is desirable to have the ability to rapidly generate thedesired concentration of peracid without significantly exceeding theupper efficacious disinfectant concentration, thereby limiting orpreventing the corrosion of certain components of the surface. In anapplication for in situ generation of peracid for bleaching of laundryor textiles, similar limitations to the concentration of peracidgenerated above that required for bleaching are also desirable.

In addition to catalyzing the production of peracids, CE-7 esterases canalso catalyze the hydrolysis of peracid to produce carboxylic acid andhydrogen peroxide. Therefore, under reaction conditions where the enzymeretains its activity for an extended period of time, it may destroy theperacid produced in the first enzyme-catalyzed reaction of ester andperoxide, producing carboxylic acid (e.g., acetic acid) as a byproductthat can impart an undesirable odor to the disinfectant solution. Thisperacid hydrolysis activity of the enzyme could also jeopardize the longterm stability of peracid-containing formulations produced by CE-7esterases over the course of several hours, or even several days orweeks, depending on the stability of the peracid in the disinfectantformulation.

Peracid solutions have a wide variety of applications. Though progresshas been made in devising efficient and effective ways to produceperacid solutions, improved methods are needed. An in situ process forproducing peracids that limits the enzyme-catalyzed production ofperacids in a peracid concentration-dependent manner would allowtargeted concentrations of peracids to be produced in a task-appropriateway.

SUMMARY OF THE INVENTION

Disclosed herein are enzyme-catalyzed processes of producing a targetconcentration of peracid. The enzyme-catalyzed production of peracids islimited in a peracid concentration-dependent manner. Also disclosedherein are processes of disinfecting surfaces or inanimate objects, andof bleaching of textiles or laundry, through the use ofperacid-containing solutions that deliver a targeted concentration ofperacid. The described processes are enabled by the first discovery thatenzymes belonging to the structural family of CE-7 esterases (e.g.,cephalosporin C deacetylases [CAHs] and acetyl xylan esterases [AXEs])exhibit significant perhydrolysis activity for converting carboxylicacid esters into peracids, and by the second discovery that the activityof said enzymes for both perhydrolysis of esters to produce peracids andfor hydrolysis of peracids to produce carboxylic acids and hydrogenperoxide decreases significantly or is inactivated as the pH of thereaction decreases over the course of the reaction that produces peracidand/or carboxylic acid. The activity of the CE-7 esterases forproduction of peracid, and optionally for hydrolysis of peracid, may becontrolled by a number of methods, including but not limited toselecting the initial pH of the reaction, or by selecting the buffer andbuffer concentration in the perhydrolysis reaction, or by a combinationof selection of initial pH and buffer and buffer concentration, suchthat a targeted concentration of peracid, or targeted range of peracidconcentration, is produced.

In one embodiment, the processes provide a means for producingenzyme-catalyzed peracid solutions having peracid concentrationssufficient to disinfect surfaces or inanimate objects and also reduce orprevent the corrosive effects associated with higher concentrations ofperacid in solution. In a second embodiment, the processes provide ameans for producing enzyme-catalyzed peracid solutions having peracidconcentrations sufficient to disinfect or remove stains from textiles orlaundry and also reduce or prevent the damaging effects associated withhigher concentrations of peracid in solution towards dyed textiles orclothing, or damaging effects associated with fabric integrity. In someembodiments the processes provide a means for producing enzyme-catalyzedperacid solutions suitable to disinfect surfaces or inanimate objectswhere the duration of the enzymatic activity is insufficient to mediatea substantial secondary enzyme-catalyzed hydrolysis of the peracidproduced in the initial enzyme-catalyzed reaction, where the secondaryenzyme-catalyzed hydrolysis of the peracid yields a carboxylic acid(e.g., acetic acid).

One way to control the amount of peracid produced by theenzyme-catalyzed reaction is to use reaction conditions that selectivelyreduce, or inactivate, the catalytic function of the enzyme. Thecatalytic activity of perhydrolase enzymes can be controlled in a numberof ways, such as altering the pH of the reaction mixture. Accordingly,the initial pH of the reaction mixture may be adjusted such that the pHof the reaction decreases as peracid is produced, ultimately resultingin the reaction mixture having a pH at which the enzyme activity issignificantly reduced or inactivated. Alternatively, when only lowconcentrations of peracid are desirable, the initial pH of the reactioncan be low enough to substantially reduce enzyme activity, resulting inonly a very short period of enzyme-catalyzed peracid production. Anotherway to control the amount of peracid produced by the enzyme-catalyzedreaction is to employ a buffer concentration in the reaction mixturesuch that its buffering capacity is limited, causing the buffer to bequickly exhausted as peracid and other reaction products (e.g.,carboxylic acid) are produced, and thereby reducing the pH of thereaction mixture and reducing, or inactivating, enzyme activity. One wayto control the amount of peracid produced by an enzyme-catalyzedreaction is to select a reaction mixture initial pH and a buffer with apKa that will cause the pH of the reaction mixture to decrease such thatthe enzymatic activity of the reaction is reduced or inactivated as thedesired amount of peracid is produced. Another approach is to use apH-sensitive enzyme with a high catalytic rate to produce a reactionwith a high initial output of peracid that causes the pH of the reactionmixture to decrease to a point at which catalytic activity issignificantly decreased or inactivated. Each of these approaches,however, requires selecting an enzyme for use in the reaction that haspH-sensitive catalytic activity, such that the ability of the enzyme tocatalyze the production of peracid is eliminated, or substantiallyreduced, when the reaction mixture reaches a desired pH. In addition,the specific activity versus reaction pH profile of the enzyme must beunderstood in order to design perhydrolysis reactions that producetargeted amount of peracid. Described herein are pH-sensitiveperhydrolase enzymes and methods of producing targeted concentrations ofperacid in a fixed period of time.

Described are aqueous peracid solutions that maintain a relativelystable concentration of peracid, i.e., within about 20% of a targetperacid concentration, following pH-mediated reduction, or inactivation,of enzyme catalyst activity. In some preferred embodiments, aqueousperacid solutions that maintain a peracid concentration within about 15%of a target peracid concentration, and more preferably within about 10%of a target peracid concentration, following pH-mediated reduction, orinactivation, of enzyme catalyst activity are provided. The stability ofthe peracid concentration can persist for hours after the reduction, orinactivation, of the enzyme-catalyzed production of peracid. In oneembodiment, the peracid concentration is stable for about 3 hours, about6 hours, about 9 hours, about 12 hours, about 15 hours, about 18 hours,about 21 hours, about 24 hours, about 30 hours, about 36 hours, about 42hours, or about 48 hours after the enzyme-catalyzed production ofperacid has ceased.

Specific examples of perhydrolases are exemplified from Bacillussubtilis (ATCC® 31954™, B. subtilis BE1010 (Payne and Jackson, J.Bacteriol 173:2278-2282 (1991)), B. subtilis ATCC® 6633™ (U.S. Pat. No.6,465,233), B. subtilis ATCC® 29233™; B. licheniformis ATCC® 14580™ (Reyet al., Genome Biol, 5(10):article 77 (2004)), Clostridium thermocellumATCC® 27405™ (Copeland et al., GENBANK® ZP_(—)00504991, B. pumilus PS213(Degrassi et al., Microbiology, 146:1585-1591 (2000)), Thermotoganeapolitana (GENBANK® AAB70869.1), Bacillus clausii KSM-K16 (GENBANK®YP_(—)175265 ), Bacillus sp. NRRL B-14911 (GENBANK® ZP_(—)01168674),Bacillus halodurans C-125 (GENBANK® NP_(—)244192), Thermoanaerobacteriumsp. JW/SL YS485 (GENBANK® AAB68821), Bacillus subtilis subsp. subtilisstr. 168 (GENBANK® NP_(—)388200), Thermotoga maritima MSB8 (GENBANK®NP_(—)227893.1), Thermoanaerobacterium saccharolyticum (GENBANK®S41858), Thermotoga lettingae (GENBANK® CP000812), Thermotogapetrophila(GENBANK® CP000702), and Thermotoga sp. RQ2 (GENBANK® CP000969).

Each of the present perhydrolase enzymes described herein shareconserved structural features (i.e., a conserved signature motif) aswell as superior perhydrolysis activity relative to otherα/β-hydrolases, which makes this family of enzymes particularly suitablefor generating peracids in situ at concentrations sufficient for use asa disinfectant and/or bleaching agent Suitable perhydrolases useful inthe present process can be identified by a conserved signature motiffound within the CE-7 family of carbohydrate esterases.

Provided herein is a process for producing a target concentration ofperoxycarboxylic acid comprising:

-   a. selecting a set of reaction components to produce a target    concentration of peroxycarboxylic acid, said reaction components    comprising:    -   1) at least one:        -   i) ester having the structure

[X]_(m)R₅

-   -   -   -   wherein X is an ester group of the formula R₆C(O)O                -   R₆ is a C1 to C7 linear, branched or cyclic                    hydrocarbyl moiety, optionally substituted with                    hydroxy 1 groups or C1 to C4 alkoxy groups, wherein                    R₆ optionally comprises one or more ether linkages                    when R₆ is C2 to C7;                -   R₅ is a C1 to C6 linear, branched, or cyclic                    hydrocarbyl moiety optionally substituted with                    hydroxyl groups; wherein each carbon atom in R₅                    individually comprises no more than one hydroxyl                    group or no more than one ester group;            -   wherein R₅ optionally comprises one or more ether                linkages;                -   m is an integer from 1 to the number of carbon atoms                    in R₅;            -   said ester having a solubility in water of at least 5                parts per million at 25° C.; or

        -   ii) glyceride having the structure

-   -   -   -   wherein R₁ is C1 to C7 straight chain or branched chain                alkyl optionally substituted with an hydroxyl or a C1 to                C4 alkoxy group and R₃ and R₄ are individually H or                R₁C(O); or

        -   iii) acetylated monosaccharide, acetylated disaccharide, or            acetylated polysaccharide;

        -   or mixtures thereof;

    -   2) a source of peroxygen;

    -   3) an enzyme catalyst having perhydrolysis activity, wherein        said enzyme catalyst comprises an enzyme having a CE-7 signature        motif that aligns with a reference sequence SEQ ID NO: 2 using        CLUSTALW, said signature motif comprising:        -   i) an RGQ motif at amino acid positions 118-120 of SEQ ID            NO:2;        -   ii) a GXSQG motif at amino acid positions 179-183 of SEQ ID            NO:2; and        -   iii) an HE motif at amino acid positions 298-299 of SEQ ID            NO:2; and        -   wherein said enzyme comprises at least 30% amino acid            identity to SEQ ID NO: 2; and

    -   4) optionally at least one buffer; and

-   b. combining the selected set of reaction components under aqueous    reaction conditions to form a reaction mixture; whereby reaction    products are formed comprising peroxycarboxylic acid; wherein the    reaction products comprising peroxycarboxylic acid reduce the    reaction mixture pH to less than about 6.0 within about 1 minute to    about 10 minutes of combining the reaction components and produce    the target concentration of peroxycarboxylic acid; wherein the    reduction in the reaction mixture pH is used to control the target    concentration of peroxycarboxylic acid produced.

Also provided herein is a process for disinfecting a hard surface orinanimate object by producing a target concentration of peroxycarboxylicacid comprising:

-   a. selecting a set of reaction components to produce a target    concentration of peroxycarboxylic acid, said reaction components    comprising:    -   1) at least one:        -   i) ester having the structure

[X]_(m)R5

-   -   -   -   wherein X is an ester group of the formula R₆C(O)O                -   R₆ is a C1 to C7 linear, branched or cyclic                    hydrocarbyl moiety, optionally substituted with                    hydroxyl groups or C1 to C4 alkoxy groups, wherein                    R₆ optionally comprises one or more ether linkages                    when R₆ is C2 to C7;                -   R₅ is a C1 to C6 linear, branched, or cyclic                    hydrocarbyl moiety optionally substituted with                    hydroxyl groups; wherein each carbon atom in R₅                    individually comprises no more than one hydroxyl                    group or no more than one ester group;            -   wherein R₅ optionally comprises one or more ether                linkages;                -   m is an integer from 1 to the number of carbon atoms                    in R₅;            -   said ester having a solubility in water of at least 5                parts per million at 25° C.; or

        -   ii) glyceride having the structure

-   -   -   -   wherein R₁ is C1 to C7 straight chain or branched chain                alkyl optionally substituted with an hydroxyl or a C1 to                C4 alkoxy group and R₃ and R₄ are individually H or                R₁C(O); or

        -   iii) acetylated monosaccharide, acetylated disaccharide, or            acetylated polysaccharide;

        -   or mixtures thereof;

    -   2) a source of peroxygen;

    -   3) an enzyme catalyst having perhydrolysis activity, wherein        said enzyme catalyst comprises an enzyme having a CE-7 signature        motif that aligns with a reference sequence SEQ ID NO: 2 using        CLUSTALW, said signature motif comprising:        -   i) an RGQ motif at amino acid positions 118-120 of SEQ ID            NO:2;        -   ii) a GXSQG motif at amino acid positions 179-183 of SEQ ID            NO:2; and        -   iii) an HE motif at amino acid positions 298-299 of SEQ ID            NO:2; and        -   wherein said enzyme comprises at least 30% amino acid            identity to SEQ ID NO: 2; and

    -   4) optionally at least one buffer;

-   b. combining the selected set of reaction components under aqueous    reaction conditions to form a reaction mixture; whereby reaction    products are formed comprising peroxycarboxylic acid; wherein the    reaction products comprising peroxycarboxylic acid reduce the    reaction mixture pH to less than about 6.0 within about 1 minute to    about 10 minutes of combining the reaction components and produce    the target concentration of peroxycarboxylic acid; wherein the    reduction in the reaction mixture pH is used to control the target    concentration of peroxycarboxylic acid produced; and

-   c. applying the peroxycarboxylic acid produced in step (b) to a hard    surface or inanimate object.

In some embodiments, the peroxycarboxylic acid produced is diluted.

In another embodiment, the catalyst is a substantially similar enzymehaving an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% identical to one or more amino acid sequencesselected from the group consisting of SEQ ID NO: 2, SEQ ID NO: 4, SEQ IDNO: 6, SEQ ID NO: 8, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 14, SEQ IDNO: 16, SEQ ID NO: 18, SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQID NO: 30, SEQ ID NO: 54, SEQ ID NO: 56, SEQ ID NO: 58, SEQ ID NO: 60,and SEQ ID NO: 62.

In another embodiment, the perhydrolase catalyst comprises an enzymehaving an amino acid sequence encoded by a nucleic acid molecule thathybridizes to a nucleic acid sequence selected from the group consistingof SEQ ID NO: 1; SEQ ID NO: 3; SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 9,SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 17, SEQ ID NO:19, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 29, SEQ ID NO: 55, SEQ IDNO: 57, SEQ ID NO: 59, and SEQ ID NO: 61 under stringent hybridizationconditions. In a preferred embodiment, the present invention includes anenzyme having perhydrolase activity encoded by isolated nucleic acidmolecule that hybridizes under stringent conditions to a nucleic acidmolecule having a nucleic acid sequence selected from the groupconsisting of SEQ ID NO: 1, SEQ ID NO: 9, SEQ ID NO: 13, and SEQ ID NO:15.

In another embodiment, the perhydrolase catalyst comprises a variantThermotoga enzyme having at least 95% amino acid sequence identity (or,in various embodiments, 96%, 97%, 98%, or 99% sequence identity), basedon the CLUSTAL method of alignment (such as CLUSTALW) with pairwisealignment default parameters of KTUPLE=1, GAP PENALTY=3, WINDOW=5 andDIAGONALS SAVED=5, when compared to SEQ ID NOs: 69, 70, 71, 72, or 73,provided that a substitution to amino acid 277 of SEQ ID NOs: 69, 70,71, 72, or 73 is selected from the group consisting of serine,threonine, valine, and alanine.

In another embodiment, the perhydrolase catalyst comprises a variantThermotoga enzyme comprising an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 69, 70, 71, 72, and 73 provided theamino acid residue 277 is selected from the group consisting of serine,threonine, valine, and alanine.

In a specific embodiment, the perhydrolase catalyst comprises a variantThermotoga neapolitana enzyme comprising amino acid sequence SEQ ID NO:69 wherein amino acid residue 277 is substituted with an amino acidselected from the group consisting of serine, threonine, valine, andalanine.

In a further specific embodiment, the perhydrolase catalyst is a variantThermotoga maritima enzyme comprising amino acid sequence SEQ ID NO: 70wherein amino acid residue 277 is substituted with an amino acidselected from the group consisting of serine, threonine, valine, andalanine.

In some aspects, the aqueous reaction mixture includes a buffer and hasa specific initial pH. The buffer may be any buffer suitable forcarrying out an enzymatic perhydrolysis reaction at the desired pH. Insome aspects, the buffer is selected from the group consisting of thesodium salt, the potassium salt or mixed sodium and potassium salts ofbicarbonate buffer, citrate buffer, methylphosphonate buffer,pyrophosphate buffer and phosphate buffer. In some aspects, the bufferis bicarbonate buffer or citrate buffer. In some aspects, the reactionmixture containing a buffer has an initial pH of about 5.5 to about 8.5.In some aspects, the reaction mixture containing a buffer has an initialpH of about 8.5. In some aspects, the reaction mixture containing abuffer has an initial pH of about 8.1. In some aspects, the reactionmixture containing a buffer has an initial pH of about 7.2. In someaspects, the reaction mixture containing a buffer has an initial pH ofabout 6.5. In some aspects, the reaction mixture containing a buffer hasan initial pH of about 6.0. In some aspects, the reaction mixturecontaining a buffer has an initial pH of about 5.5.

In some aspects, the buffer included in the aqueous reaction mixture canestablish the initial pH of the mixture. In some aspects, the bufferproduces an aqueous reaction mixture with an initial pH of about 5.5 toabout 8.5. In some aspects, the buffer produces an aqueous reactionmixture with an initial pH of about 8.1. In some aspects, the bufferproduces an aqueous reaction mixture with an initial pH of about 7.2. Insome aspects, the buffer produces an aqueous reaction mixture with aninitial pH of about 6.5. In some aspects, the buffer produces an aqueousreaction mixture with an initial pH of about 6.0. In some aspects, thebuffer produces an aqueous reaction mixture with an initial pH of about5.5.

In some aspects, the aqueous reaction mixture may include at least onebuffer having a specific concentration. The buffer may be any buffersuitable for carrying out an enzymatic perhydrolysis reaction. In someaspects, the reaction mixture contains buffer at a concentration ofabout 0.01 mM to about 200 mM. In some aspects, the reaction mixturecontains buffer at a concentration of about 50 mM. In some aspects, thereaction mixture contains buffer having a concentration of about 25 mMto about 0.1 mM. In some aspects, the reaction mixture containsbicarbonate buffer having a concentration of about 25 mM to about 0.1mM. In some aspects, the reaction mixture contains buffer having aconcentration of less than about 5 mM. In some aspects, the reactionmixture contains bicarbonate buffer having a concentration of less thanabout 5 mM.

In a preferred embodiment, the substrate is selected from the groupconsisting of: monoacetin; diacetin; triacetin; monopropionin;dipropionin; tripropionin; monobutyrin; dibutyrin; tributyrin; glucosepentaacetate; xylose tetraacetate; acetylated xylan; acetylated xylanfragments; βD-ribofuranose-1,2,3,5-tetraacetate;tri-O-acetyl-D-galactal; tri-O-acetyl-glucal; monoesters or diesters of1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol,1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,2-pentanediol,2,5-pentanediol, 1,6-pentanediol, 1,2-hexanediol, 2,5-hexanediol,1,6-hexanediol; and mixtures thereof.

BRIEF DESCRIPTION OF THE BIOLOGICAL SEQUENCES

The following sequences comply with 37 C.F.R. 1.821-1.825 (“Requirementsfor Patent Applications Containing Nucleotide Sequences and/or AminoAcid Sequence Disclosures—the Sequence Rules”) and are consistent withWorld Intellectual Property Organization (WIPO) Standard ST.25 (1998)and the sequence listing requirements of the European Patent Convention(EPC) and the Patent Cooperation Treaty (PCT) Rules 5.2 and 49.5(a-bis),and Section 208 and Annex C of the Administrative Instructions. Thesymbols and format used for nucleotide and amino acid sequence datacomply with the rules set forth in 37 C.F.R. §1.822.

SEQ ID NO: 1 is the nucleic acid sequence of the cephalosporin Cdeacetylase (cah) coding region from Bacillus subtilis ATCC® 31954™.

SEQ ID NO: 2 is the deduced amino acid sequence of the cephalosporin Cdeacetylase from Bacillus subtilis ATCC® 31954™.

SEQ ID NO: 3 is the nucleic acid sequence of the cephalosporin Cdeacetylase coding region from B. subtilis subsp. subtilis str. 168.

SEQ ID NO: 4 is the deduced amino acid sequence of the cephalosporin Cdeacetylase from B. subtilis subsp. subtilis str. 168, and is identicalto the deduced amino acid sequence of the cephalosporin C deacetylasefrom B. subtilis BE1010.

SEQ ID NO: 5 is the nucleic acid sequence of the cephalosporinacetylesterase coding region from B. subtilis ATCC® 6633™.

SEQ ID NO: 6 is the deduced amino acid sequence of the cephalosporinacetylesterase from B. subtilis ATCC® 6633™.

SEQ ID NO: 7 is the nucleic acid sequence of the cephalosporin Cdeacetylase coding region from B. licheniformis ATCC® 14580™.

SEQ ID NO: 8 is the deduced amino acid sequence of the cephalosporin Cdeacetylase from B. licheniformis ATCC® 14580™.

SEQ ID NO: 9 is the nucleic acid sequence of the acetyl xylan esterasecoding region from B. pumilus PS213.

SEQ ID NO: 10 is the deduced amino acid sequence of the acetyl xylanesterase from B. pumilus PS213.

SEQ ID NO: 11 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Clostridium thermocellum ATCC® 27405™.

SEQ ID NO: 12 is the deduced amino acid sequence of the acetyl xylanesterase from Clostridium thermocellum ATCC® 27405™.

SEQ ID NO: 13 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermotoga neapolitana.

SEQ ID NO: 14 is the deduced amino acid sequence of the acetyl xylanesterase from Thermotoga neapolitana.

SEQ ID NO: 15 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermotoga maritima MSB8.

SEQ ID NO: 16 is the deduced amino acid sequence of the acetyl xylanesterase from Thermotoga maritima MSB8.

SEQ ID NO: 17 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermo anaerobacterium sp. JW/SLYS485.

SEQ ID NO: 18 is the deduced amino acid sequence of the acetyl xylanesterase from Thermoanaerobacterium sp. JW/SL YS485.

SEQ ID NO: 19 is the nucleic acid sequence of the cephalosporin Cdeacetylase coding region from Bacillus sp. NRRL B-14911.

SEQ ID NO: 20 is the deduced amino acid sequence of the cephalosporin Cdeacetylase from Bacillus sp. NRRL B-14911.

SEQ ID NO: 21 is the nucleic acid sequence of the cephalosporin Cdeacetylase coding region from Bacillus halodurans C-125.

SEQ ID NO: 22 is the deduced amino acid sequence of the cephalosporin Cdeacetylase from Bacillus halodurans C-125.

SEQ ID NO: 23 is the nucleic acid sequence of the cephalosporin Cdeacetylase coding region from Bacillus clausii KSM-K16.

SEQ ID NO: 24 is the deduced amino acid sequence of the cephalosporin Cdeacetylase from Bacillus clausii KSM-K16.

SEQ ID NOs: 25 and 26 are primers used to PCR amplify perhydrolase genesfrom Bacillus subtilis species for construction of pSW194 and pSW189.

SEQ ID NO: 27 is the nucleic acid sequence of the PCR product clonedinto pSW194.

SEQ ID NO: 28 is the nucleic acid sequence of the PCR product clonedinto pSW189.

SEQ ID NO: 29 is the nucleic acid sequence of the Bacillus subtilisATCC® 29233™ cephalosporin C deacetylase (cah) gene.

SEQ ID NO: 30 is the deduced amino acid sequence of the Bacillussubtilis ATCC® 29233™ cephalosporin C deacetylase (CAH).

SEQ ID NOs: 31 and 32 are primers used to PCR amplify the Bacilluslicheniformis ATCC® 14580™ cephalosporin C deacetylase gene forconstruction of pSW191.

SEQ ID NOs: 33 and 34 are primers used to PCR amplify the Bacilluspumilus PS213acetyl xylan esterase coding sequence (GENBANK® AJ249957)for construction of pSW195.

SEQ ID NO: 35 is the nucleic acid sequence of the kanamycin resistancegene.

SEQ ID NO: 36 is the nucleic acid sequence of plasmid pKD13.

SEQ ID NOs; 37 and 38 are primers used to generate a PCR productencoding the kanamycin gene flanked by regions having homology to thekatG catalase gene in E. coli MG1655. The product was used to disruptthe endogenous katG gene.

SEQ ID NO: 39 is the nucleic acid sequence of the PCR product encodingthe kanamycin resistance gene flanked by regions having homology to thekatG catalase gene in E. coli MG1655. The product was used to disruptthe endogenous katG gene.

SEQ ID NO: 40 is the nucleic acid sequence of the katG catalase gene inE. coli MG1655.

SEQ ID NO: 41 is the deduced amino acid sequence of the KatG catalase inE. coli MG1655.

SEQ ID NO: 42 is the nucleic acid sequence of plasmid pKD46.

SEQ ID NOs: 43 and 44 are primers used to confirm the disruption of thekatG gene.

SEQ ID NO: 45 is the nucleic acid sequence of plasmid pCP20.

SEQ ID NOs: 46 and 47 are primers used to generate a PCR productencoding the kanamycin gene flanked by regions having homology to thekatE catalase gene in E. coli MG1655. The product was used to disruptthe endogenous katE gene.

SEQ ID NO: 48 is the nucleic acid sequence of the PCR product encodingthe kanamycin resistance gene flanked by regions having homology to thekatE catalase gene in E. coli MG1655. The product was used to disruptthe endogenous katE gene.

SEQ ID NO: 49 is the nucleic acid sequence of the katE catalase gene inE. coli MG1655.

SEQ ID NO: 50 is the deduced amino acid sequence of the KatE catalase inE. coli MG1655.

SEQ ID NOs: 51 and 52 are primers used to confirm disruption of the katEgene in the single knockout strain E. coli MG1655 ΔkatE, and in thedouble-knockout strain E. coli MG1655ΔkatG ΔkatE, herein referred to asE. coli KLP18.

SEQ ID NO: 53 is the amino acid sequence of the region encompassingamino acids residues 118 through 299 of SEQ ID NO: 2.

SEQ ID NO: 54 is the deduced amino acid sequence of the acetyl xylanesterase from Thermoanaerobacterium saccharolyticum (GENBANK® AccessionNo. S41858).

SEQ ID NO: 55 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermotoga lettingae.

SEQ ID NO: 56 is the deduced amino acid sequence of the acetyl xylanesterase from Thermotoga lettingae.

SEQ ID NO: 57 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermotoga petrophila.

SEQ ID NO: 58 is the deduced amino acid sequence of an acetyl xylanesterase from Thermotoga petrophila.

SEQ ID NO: 59 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermotoga sp. RQ2 identified herein as “RQ2(a)”.

SEQ ID NO: 60 is the deduced amino acid sequence of an acetyl xylanesterase (GENBANK® Accession No. ACB09222) from Thermotoga sp. RQ2identified herein as “RQ2(a)”.

SEQ ID NO: 61 is the nucleic acid sequence of the acetyl xylan esterasecoding region from Thermotoga sp. RQ2 identified herein as “RQ2(b)”.

SEQ ID NO: 62 is the deduced amino acid sequence of an acetyl xylanesterase (GENBANK® Accession No. ACB08860) from Thermotoga sp. RQ2identified herein as “RQ2(b)”.

SEQ ID NOs: 63 and 64 are primers used to PCR amplify the Thermotogamaritima MSB8 acetyl xylan esterase gene (GENBANK accession#NP_(—)227893.1).

SEQ ID NO: 65 is the PCR amplified nucleic acid sequence of theThermotoga maritima MSB8 acetyl xylan esterase used to generate pSW207.

SEQ ID NOs: 66 and 67 are primers used to PCR amplify the Thermotoganeapolitana acetyl xylan esterase gene (GENBANK® 58632) for constructionof pSW196.

SEQ ID NO: 68 is the nucleic acid sequence of the codon-optimizedversion of the Thermotoga neapolitana acetyl xylan esterase gene inplasmid pSW196.

SEQ ID NO: 69 represents the deduced amino acid sequence of the acetylxylan esterase variants derived from the wild-type sequence of an acetylxylan esterase from Thermotoga neapolitana, where the Xaa residue atposition 277 is Ala, Val, Ser, or Thr.

SEQ ID NO: 70 represents the deduced amino acid sequence of the acetylxylan esterase variants derived from the wild-type sequence of an acetylxylan esterase from Thermotoga maritima MSB8, where the Xaa residue atposition 277 is Ala, Val, Ser, or Thr.

SEQ ID NO: 71 represents the deduced amino acid sequence of the acetylxylan esterase variants derived from the wild-type sequence of an acetylxylan esterase from Thermotoga lettingae, where the Xaa residue atposition 277 is Ala, Val, Ser, or Thr.

SEQ ID NO: 72 represents the deduced amino acid sequence of the acetylxylan esterase variants derived from the wild-type sequence of an acetylxylan esterase from Thermotoga petrophila, where the Xaa residue atposition 277 is Ala, Val, Ser, or Thr.

SEQ ID NO: 73 represents the deduced amino acid sequence of the acetylxylan esterase variants derived from the wild-type sequence of an acetylxylan esterase from Thermotoga sp. RQ2 described herein as “RQ2(a)”,where the Xaa residue at position 277 is Ala, Val, Ser, or Thr.

DETAILED DESCRIPTION

The stated problems have been solved by the discovery that enzymesbelonging to the CE-7 carbohydrate esterase family exhibit significantperhydrolysis activity for converting carboxylic acid ester substratesto peracids that can be regulated by controlling the pH of the reactionmixture. Elucidation of the specific activity versus pH profile of CE-7carbohydrate esterases allows for the control of enzyme-drivenproduction of peracids by varying reaction parameters including bufferconcentration and pH. Having this understanding, this family ofstructurally related enzymes can be used to generate stable, targetedconcentrations of peracids for disinfection and/or bleachingapplications.

In this disclosure, a number of terms and abbreviations are used. Thefollowing definitions apply unless specifically stated otherwise.

As used herein, the term “comprising” means the presence of the statedfeatures, integers, steps, or components as referred to in the claims,but does not preclude the presence or addition of one or more otherfeatures, integers, steps, components or groups thereof. The term“comprising” is intended to include embodiments encompassed by the terms“consisting essentially of” and “consisting of”. Similarly, the term“consisting essentially of” is intended to include embodimentsencompassed by the term “consisting of”.

As used herein, the term “about” modifying the quantity of an ingredientor reactant employed refers to variation in the numerical quantity thatcan occur, for example, through typical measuring and liquid handlingprocedures used for making concentrates or use solutions in the realworld; through inadvertent error in these procedures; throughdifferences in the manufacture, source, or purity of the ingredientsemployed to make the compositions or carry out the methods; and thelike. The term “about” also encompasses amounts that differ due todifferent equilibrium conditions for a composition resulting from aparticular initial mixture. Whether or not modified by the term “about”,the claims include equivalents to the quantities.

As used herein, the term “peracid” is synonymous with peroxyacid,peroxycarboxylic acid, peroxy acid, percarboxylic acid and peroxoicacid.

As used herein, the term “peracetic acid” is abbreviated as “PAA” and issynonymous with peroxyacetic acid, ethaneperoxoic acid and all othersynonyms of CAS Registry Number 79-21-0.

As used herein, the term “monoacetin” is synonymous with glycerolmonoacetate, glycerin monoacetate, and glyceryl monoacetate.

As used herein, the term “diacetin” is synonymous with glyceroldiacetate; glycerin diacetate, glyceryl diacetate, and all othersynonyms of CAS Registry Number 25395-31-7.

As used herein, the term “triacetin” is synonymous with glycerintriacetate; glycerol triacetate; glyceryl triacetate,1,2,3-triacetoxypropane, 1,2,3-propanetriol triacetate and all othersynonyms of CAS Registry Number 102-76-1.

As used herein, the term “monobutyrin” is synonymous with glycerolmonobutyrate, glycerin monobutyrate, and glyceryl monobutyrate.

As used herein, the term “dibutyrin” is synonymous with glyceroldibutyrate and glyceryl dibutyrate.

As used herein, the term “tributyrin” is synonymous with glyceroltributyrate, 1,2,3-tributyrylglycerol, and all other synonyms of CASRegistry Number 60-01-5.

As used herein, the term “monopropionin” is synonymous with glycerolmonopropionate, glycerin monopropionate, and glyceryl monopropionate.

As used herein, the term “dipropionin” is synonymous with glyceroldipropionate and glyceryl dipropionate.

As used herein, the term “tripropionin” is synonymous with glyceryltripropionate, glycerol tripropionate, 1,2,3-tripropionylglycerol, andall other synonyms of CAS Registry Number 139-45-7.

As used herein, the term “ethyl acetate” is synonymous with aceticether, acetoxyethane, ethyl ethanoate, acetic acid ethyl ester, ethanoicacid ethyl ester, ethyl acetic ester and all other synonyms of CASRegistry Number 141-78-6.

As used herein, the term “ethyl lactate” is synonymous with lactic acidethyl ester and all other synonyms of CAS Registry Number 97-64-3.

As used herein, the terms “acetylated sugar” and “acetylated saccharide”refer to mono-, di- and polysaccharides comprising at least one acetylgroup. Examples include, but are not limited to, glucose pentaacetate,xylose tetraacetate, acetylated xylan, acetylated xylan fragments,β-D-ribofuranose-1,2,3,5-tetraacetate, tri-O-acetyl-D-galactal, andtri-O-acetyl-glucal.

As used herein, the terms “hydrocarbyl”, “hydrocarbyl group”, and“hydrocarbyl moiety” mean a straight chain, branched or cyclicarrangement of carbon atoms connected by single, double, or triplecarbon to carbon bonds and/or by ether linkages, and substitutedaccordingly with hydrogen atoms. Such hydrocarbyl groups may bealiphatic and/or aromatic. Examples of hydrocarbyl groups includemethyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, cyclopropyl,cyclobutyl, pentyl, cyclopentyl, methylcyclopentyl, hexyl, cyclohexyl,benzyl, and phenyl. In a preferred embodiment, the hydrocarbyl moiety isa straight chain, branched or cyclic arrangement of carbon atomsconnected by single carbon to carbon bonds and/or by ether linkages, andsubstituted accordingly with hydrogen atoms.

As used herein, the terms “monoesters” and “diesters” of 1,2-ethanediol,1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol,2,3-butanediol, 1,4-butanediol, 1,2-pentanedioI, 2,5-pentanediol,1,6-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 1,6-hexanediol, referto said compounds comprising at least one ester group of the formulaRC(O)O, wherein R is a C1 to C7 linear hydrocarbyl moiety.

As used herein, the terms “suitable enzymatic reaction mixture”,“components suitable for in situ generation of a peracid”, “suitablereaction components”, “selected set of reaction components”, and“suitable aqueous reaction mixture” refer to the materials and water inwhich the reactants and enzyme catalyst come into contact. The reactioncomponents are selected such that the pH of the reaction mixture is usedto control the production of the desired target concentration ofperoxycarboxylic acid by decreasing and/or inactivating the enzymecatalyst's perhydrolysis activity.

As used herein, the term “reaction products” will refer to the mixtureof compounds formed within the reaction mixture after combining theselected reaction components. The reaction products are comprised of theenzymatically-generated peroxycarboxylic acid (e.g., peracetic acid) aswell as one or more hydrolysis products (enzymatic and/or chemicalhydrolysis products), such as the corresponding carboxylic acid (e.g.,acetic acid). In one embodiment, combining the selected set of reactioncomponents generates a reaction mixture capable of forming reactionproducts that reduce the pH of the reaction mixture whereby theperhydrolysis activity of the enzyme catalyst is substantially decreasedand/or inactivated within 10 minutes of combining the reactioncomponents, preferably within about 1 minute to about 10 minutes. In oneembodiment, the perhydrolysis activity of the enzyme catalyst is reducedat least 80% in 10 minutes or less after combining the reactioncomponents. The reaction products provide a reaction mixture pH suitableto control the amount of enzymatically-generated peroxycarboxylic acid.The initial reaction pH will be dependent on a number of variables,including reaction component concentrations, reaction temperature, thepresence or absence of a buffer, the buffer pKa, and the bufferconcentration. In one embodiment, the pH of the reaction mixture dropsbelow about 6.0 within 10 minutes of combining the selected set ofreaction components. In another embodiment, the reaction products reducethe reaction mixture pH to less than about 6.0 within about 1 minute toabout 10 minutes of combining the reaction components.

The components of the suitable aqueous reaction mixture are providedherein and those skilled in the art appreciate the range of componentvariations suitable for this process. In one embodiment, the suitableenzymatic reaction mixture produces peracid in situ upon combining thereaction components. As such, the reaction components may be provided asa multicomponent system wherein one or more of the reaction componentsremains separated until use. The design of systems and means forseparating and combining multiple active components are known in the artand generally will depend upon the physical form of the individualreaction components. For example, multiple active fluids (liquid-liquid)systems typically use multichamber dispenser bottles or two-phasesystems (U.S. Patent Application Pub. No. 2005/0139608; U.S. Pat. No.5,398,846; U.S. Pat. No. 5,624,634; U.S. Pat. No. 6,391,840; E.P. Patent0807156B1; U.S. Patent Appln. Pub. No. 2005/0008526; and PCT PublicationNo. WO 00/11713A1) such as found in some bleaching applications whereinthe desired bleaching agent is produced upon mixing the reactive fluids.Other forms of multicomponent systems used to generate peracid mayinclude, but are not limited to those designed for one or more solidcomponents or combinations of solid-liquid components, such as powders(e.g., many commercially available bleaching composition, U.S. Pat. No.5,116,575), multi-layered tablets (U.S. Pat. No. 6,210,639), waterdissolvable packets having multiple compartments (U.S. Pat. No.6,995,125) and solid agglomerates that react upon the addition of water(U.S. Pat. No. 6,319,888).

One embodiment provides, a process for producing a targetedconcentration of peroxycarboxylic acid by controlling the catalyticactivity of an enzyme, comprising: combining selected reactioncomponents, under suitable aqueous reaction conditions, to produce atarget concentration of peroxycarboxylic acid, said reaction componentscomprising:

a first mixture comprising:

-   -   i) an enzyme catalyst having perhydrolase activity, said enzyme        catalyst comprising an enzyme having a CE-7 signature motif; and    -   ii) a carboxylic acid ester substrate, said first mixture        optionally comprising a component selected from the group        consisting of an inorganic or organic buffer, a corrosion        inhibitor, a wetting agent, and combinations thereof; and

a second mixture comprising a source of peroxygen and water, said secondmixture optionally comprising a chelating agent.

In a further related embodiment, the carboxylic acid ester substrate inthe first mixture of the formulation is selected from the groupconsisting of:

-   -   i) esters having the structure

[X]_(m)R₅

-   -   wherein X=an ester group of the formula R₆—C(O)O    -   R₆=C1 to C7 linear, branched or cyclic hydrocarbyl moiety,        optionally substituted with hydroxyl groups or C1 to C4 alkoxy        groups, wherein R₆ optionally comprises one or more ether        linkages for R₆=C2 to C7;    -   R₅=a C1 to C6 linear, branched, or cyclic hydrocarbyl moiety        optionally substituted with hydroxyl groups; wherein each carbon        atom in R₅ individually comprises no more than one hydroxyl        group or no more than one ester group; wherein R₅ optionally        comprises one or more ether linkages;    -   m=1 to the number of carbon atoms in R₅; and    -   wherein said esters have a solubility in water of at least 5 ppm        at 25° C.;    -   ii) glycerides having the structure

-   -   wherein R₁=C1 to C7 straight chain or branched chain alkyl        optionally substituted with an hydroxyl or a C1 to C4 alkoxy        group and R₃ and R₄ are individually H or R₁C(O); and    -   iii) acetylated saccharides selected from the group consisting        of acetylated monosaccharides, acetylated disaccharides, and        acetylated polysaccharides;

In another embodiment, the carboxylic acid ester substrate in the firstmixture of the formulation is defined by the following formula:

wherein R₁=C1 to C7 straight chain or branched chain alkyl optionallysubstituted with an hydroxyl or a C1 to C4 alkoxy group and R₂=C1 to C10straight chain or branched chain alkyl, alkenyl, alkynyl, aryl,alkylaryl, alkylheteroaryl, heteroaryl, (CH₂CH₂—O)_(n)H or(CH₂CH(CH₃)—O)_(n)H and n=1 to 10.

In a preferred embodiment, R₆ is C1 to C7 linear hydrocarbyl moiety,optionally substituted with hydroxyl groups or C1 to C4 alkoxy groups,optionally comprising one or more ether linkages. In a further preferredembodiment, R₆ is C2 to C7 linear hydrocarbyl moiety, optionallysubstituted with hydroxyl groups, and/or optionally comprising one ormore ether linkages.

In another embodiment, the carboxylic acid ester substrate is selectedfrom the group consisting of: monoacetin; diacetin; triacetin;monopropionin; dipropionin; tripropionin; monobutyrin; dibutyrin;tributyrin; glucose pentaacetate; xylose tetraacetate; acetylated xylan;acetylated xylan fragments; β-D-ribofuranose-1,2,3,5-tetraacetate;tri-O-acetyl-D-galactal; tri-O-acetyl-glucal; monoesters or diesters of1,2-ethanediol, 1,2-propanedlol, 1,3-propanediol, 1,2-butanediol,1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,2-pentanediol,2,5-pentanediol, 1,6-pentanediol, 1,2-hexanediol, 2,5-hexanedioI,1,6-hexanediol; and mixtures thereof.

In another embodiment, the carboxylic acid ester is selected from thegroup consisting of monoacetin, diacetin, triacetin, and combinationsthereof. In another embodiment, the carboxylic acid ester is anacetylated saccharide. In another embodiment, the substrate is a C1 toC6 polyol comprising one or more ester groups. In a preferredembodiment, one or more of the hydroxyl groups on the C1 to C6 polyolare substituted with one or more acetoxy groups (e.g. 1,3-propanedioldiacetate, 1,4-butanediol diacetate, etc.). In another embodiment, theenzyme catalyst is a particulate solid. In another embodiment, the firstreaction mixture described above is a solid tablet or powder.

As used herein, the term “perhydrolysis” is defined as the reaction of aselected substrate with peroxide to form a peracid. Typically, inorganicperoxide is reacted with the selected substrate in the presence of acatalyst to produce the peracid. Alternatively, hydrogen peroxide can begenerated in situ by the reaction of a substrate and oxygen catalyzed byan enzyme having oxidase activity (e.g., glucose oxidase, alcoholoxidase, monoamine oxidase, lactate oxidase, amino acid oxidase). Asused herein, the term “chemical perhydrolysis” includes perhydrolysisreactions in which a substrate (a peracid precursor) is combined with asource of hydrogen peroxide wherein peracid is formed in the absence ofan enzyme catalyst.

As used herein, the term “perhydrolase activity” refers to the catalystactivity per unit mass (for example, milligram) of protein, dry cellweight, or immobilized catalyst weight.

As used herein, “one unit of enzyme activity” or “one unit of activity”or “U” is defined as the amount of perhydrolase activity required forthe production of 1 μmol of peracid product per minute at a specifiedtemperature.

As used herein, the terms “enzyme catalyst” and “perhydrolase catalyst”refer to a catalyst comprising an enzyme having perhydrolysis activityand may be in the form of a whole microbial cell, permeabilizedmicrobial cell(s), one or more cell components of a microbial cellextract, partially purified enzyme, or purified enzyme. The enzymecatalyst may also be chemically modified (e.g., by pegylation or byreaction with cross-linking reagents). The perhydrolase catalyst mayalso be immobilized on a soluble or insoluble support using methodswell-known to those skilled in the art; see for example, Immobilizationof Enzymes and Cells; Gordon F. Bickerstaff, Editor; Humana Press,Totowa, N.J., USA; 1997. As described herein, all of the present enzymeshaving perhydrolysis activity are structurally members of thecarbohydrate family esterase family 7 (CE-7 family) of enzymes (seeCoutinho, P. M., Henrissat, B. “Carbohydrate-active enzymes: anintegrated database approach” in Recent Advances in CarbohydrateBioengineering, H. J. Gilbert, G. Davies, B. Henrissat and B. Svenssoneds., (1999) The Royal Society of Chemistry, Cambridge, pp. 3-12.).

Members of the CE-7 family include cephalosporin C deacetylases (CAHs;E.C. 3.1.1.41) and acetyl xylan esterases (AXEs; E.C. 3.1.1.72). Membersof the CE-7 esterase family share a conserved signature motif (Vincentet al, J. Mol. Biol., 330:593-606 (2003)). Perhydrolases comprising theCE-7 signature motif and/or a substantially similar structure aresuitable for use in the present invention. Means to identifysubstantially similar biological molecules are well known in the art(e.g. sequence alignment protocols, nucleic acid hybridizations,presence of a conserved signature motif, etc.). In one aspect, theenzyme catalyst in the present process comprises a substantially similarenzyme having at least 30%, preferably at least 33%, more preferably atleast 40%, more preferably at least 50%, even more preferably at least60%, yet even more preferable at least 70%, yet even more preferably atleast 80%, yet even more preferably at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98%, or 99% amino acid identity to the sequences providedherein. The nucleic acid molecules encoding the present CE-7carbohydrate esterases are also provided herein. In a furtherembodiment, the perhydrolase catalyst useful in the present process isencoded by a nucleic acid molecule that hybridizes stringent conditionsto one of the present nucleic acid molecules.

As used herein, the terms “cephalosporin C deacetylase” and“cephalosporin C acetyl hydrolase” refers to an enzyme (E.C. 3.1.1.41)that catalyzes the deacetylation of cephalosporins such as cephalosporinC and 7-aminocephalosporanic acid (Mitsushima et al, Appl. Environ.Microbiol. 61(6): 2224-2229 (1995); U.S. Pat. No. 5,528,152; and U.S.Pat. No. 5,338,676). As described herein, several cephalosporin Cdeacetylases are provided having significant perhydrolysis activity.

As used herein, “acetyl xylan esterases” refers to an enzyme (E.C.3.1.1.72; AXEs) that catalyzes the deacetylation of acetylated xylansand other acetylated saccharides. As illustrated herein, several enzymesclassified as acetyl xylan esterases are provided having significantperhydrolase activity.

As used herein, the term “Bacillus subtilis (ATCC® 31954™)” refers to abacterial cell deposited to the American Type Culture Collection (ATCC®)having international depository accession number ATCC® 31954™. Bacillussubtilis ATCC® 31954™ has been reported to have an ester hydrolase(“diacetinase”) activity capable of hydrolyzing glycerol esters having2-carbon to 8-carbon acyl groups, especially diacetin (U.S. Pat. No.4,444,886; herein incorporated by reference in its entirety). Asdescribed herein, an enzyme having significant perhydrolase activity hasbeen isolated from B. subtilis ATCC® 31954™ and is provided as SEQ IDNO: 2. The amino acid sequence of the isolated enzyme has 100% aminoacid identity to the cephalosporin C deacetylase provided by GENBANK®Accession No. BAA01729.1.

As used herein, the term “Bacillus subtilis BE1010” refers to the strainof Bacillus subtilis as reported by Payne and Jackson (J. Bacteriol.173:2278-2282 (1991)). Bacillus subtilis BE1010 is a derivative Bacillussubtilis subsp. subtilis strain BR151 (ATCC® 33677™) having achromosomal deletion in the genes encoding subtilisin and neutralprotease. As described herein, an enzyme having significant perhydrolaseactivity has been isolated from B. subtilis BE1010 and is provided asSEQ ID NO: 4. The amino acid sequence of the isolated enzyme has 100%amino acid identity to the cephalosporin C deacetylase reported inBacillus subtilis subsp. subtilis strain 168 (Kunst et al, Nature,390:249-256 (1997)).

As used herein, the term “Bacillus subtilis ATCC® 29233™” refers to astrain of Bacillus subtilis deposited to the American Type CultureCollection (ATCC) having international depository accession number ATCC®29233™. As described herein, an enzyme having significant perhydrolaseactivity has been isolated and sequenced from B. subtilis ATCC® 29233and is provided as SEQ ID NO: 30.

As used herein, the term “Clostridium thermocellum ATCC® 27405™” refersto a strain of Clostridium thermocellum deposited to the American TypeCulture Collection (ATCC®) having international depository accessionnumber ATCC® 27405™. The amino acid sequence of the enzyme havingperhydrolase activity from C. thermocellum ATCC® 27405™ is provided asSEQ ID NO: 12.

As used herein, the term “Bacillus subtilis ATCC® 6633™” refers to abacterial cell deposited to the American Type Culture Collection (ATCC®)having international depository accession number ATCC® 6633™. Bacillussubtilis ATCC® 6633™ has been reported to have cephalosporinacetylhydrolase activity (U.S. Pat. No. 6,465,233). The amino acidsequence of the enzyme having perhydrolase activity from B. subtilisATCC® 6633™ is provided as SEQ ID NO: 6.

As used herein, the term “Bacillus licheniformis ATCC® 14580™” refers toa bacterial cell deposited to the American Type Culture Collection(ATCC) having international depository accession number ATCC® 14580™.Bacillus licheniformis ATCC® 14580™ has been reported to havecephalosporin acetylhydrolase activity (GENBANK® YP_(—)077621). Theamino acid sequence of the enzyme having perhydrolase activity from B.licheniformis ATCC® 14580™ is provided as SEQ ID NO: 8.

As used herein, the term “Bacillus pumilus PS213” refers to a bacterialcell reported to have acetyl xylan esterase activity (GENBANK®AJ249957). The amino acid sequence of the enzyme having perhydrolaseactivity from Bacillus pumilus PS213 is provided as SEQ ID NO: 10.

As used herein, the term “Thermotoga neapolitana” refers to a strain ofThermotoga neapolitana reported to have acetyl xylan esterase activity(GENBANK® AAB70869). The amino acid sequence of the enzyme havingperhydrolase activity from Thermotoga neapolitana is provided as SEQ IDNO: 14.

As used herein, the term “Thermotoga maritima MSB8” refers to abacterial cell reported to have acetyl xylan esterase activity (GENBANK®NP_(—)227893.1). The amino acid sequence of the enzyme havingperhydrolase activity from Thermotoga maritima MSB8 is provided as SEQID NO: 16.

As used herein, the term “Bacillus clausii KSM-K16” refers to abacterial cell reported to have cephalosporin-C deacetylase activity(GENBANK® YP_(—)175265). The amino acid sequence of the enzyme havingperhydrolase activity from Bacillus clausii KSM-K16 is provided as SEQID NO: 24.

As used herein, the term “Thermoanearobacterium saccharolyticum” refersto a bacterial strain reported to have acetyl xylan esterase activity(GENBANK® S41858), The amino acid sequence of the enzyme havingperhydrolase activity from Thermoanearobacterium saccharolyticum isprovided as SEQ ID NO: 54.

As used herein, the term “Thermotoga lettingae” refers to a bacterialcell reported to have acetyl xylan esterase activity (GENBANK®CP000812). The deduced amino acid sequence of the enzyme havingperhydrolase activity from Thermotoga lettingae is provided as SEQ IDNO: 56.

As used herein, the term “Thermotoga petrophila” refers to a bacterialcell reported to have acetyl xylan esterase activity (GENBANK®CP000702). The deduced amino acid sequence of the enzyme havingperhydrolase activity from Thermotoga lettingae is provided as SEQ IDNO: 58.

As used herein, the term “Thermotoga sp. RQ2” refers to a bacterial cellreported to have acetyl xylan esterase activity (GENBANK® CP000969). Twodifferent acetyl xylan esterases have been identified from Thermotogasp. RQ2 and are referred to herein as “RQ2(a)” (the deduced amino acidsequence provided as SEQ ID NO: 60) and “RQ2(b)” (the deduced amino acidsequence provided as SEQ ID NO: 62).

As used herein, an “isolated nucleic acid molecule” and “isolatednucleic acid fragment” will be used interchangeably and refers to apolymer of RNA or DNA that is single- or double-stranded, optionallycontaining synthetic, non-natural or altered nucleotide bases. Anisolated nucleic acid molecule in the form of a polymer of DNA may becomprised of one or more segments of cDNA, genomic DNA or synthetic DNA.

The term “amino acid” refers to the basic chemical structural unit of aprotein or polypeptide. The following abbreviations are used herein toidentify specific amino acids:

Three-Letter One-Letter Amino Acid Abbreviation Abbreviation Alanine AlaA Arginine Arg R Asparagine Asn N Aspartic acid Asp D Cysteine Cys CGlutamine Gln Q Glutamic acid Glu E Glycine Gly G Histidine His HIsoleucine Ile I Leucine Leu L Lysine Lys K Methionine Met MPhenylalanine Phe F Proline Pro P Serine Ser S Threonine Thr TTryptophan Trp W Tyrosine Tyr Y Valine Val V Any amino acid Xaa X (or asdefined herein)

As used herein, “substantially similar” refers to nucleic acid moleculeswherein changes in one or more nucleotide bases results in the addition,substitution, or deletion of one or more amino acids, but does notaffect the functional properties (i.e., perhydrolytic activity) of theprotein encoded by the DNA sequence. As used herein, “substantiallysimilar” also refers to an enzyme having an amino acid sequence that isat least 30%, preferably at least 33%, more preferably at least 40%,more preferably at least 50%, even more preferably at least 60%, evenmore preferably at least 70%, even more preferably at least 80%, yeteven more preferably at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% identical to the amino acid sequences reported hereinwherein the resulting enzyme retains the present functional properties(i.e., perhydrolytic activity). “Substantially similar” may also referto an enzyme having perhydrolytic activity encoded by nucleic acidmolecules that hybridize under stringent conditions to the nucleic acidmolecules reported herein. It is therefore understood that the inventionencompasses more than the specific exemplary sequences.

For example, it is well known in the art that alterations in a genewhich result in the production of a chemically equivalent amino acid ata given site, but do not affect the functional properties of the encodedprotein are common. For the purposes of the present inventionsubstitutions are defined as exchanges within one of the following fivegroups:

1. Small aliphatic, nonpolar or slightly polar residues: Ala, Ser, Thr(Pro, Gly);

2. Polar, negatively charged residues and their amides: Asp, Asn, Glu,Gin;

3. Polar, positively charged residues: His, Arg, Lys;

4. Large aliphatic, nonpolar residues: Met, Leu, He, Val (Cys); and

5. Large aromatic residues: Phe, Tyr, Trp.

Thus, a codon for the amino acid alanine, a hydrophobic amino acid, maybe substituted by a codon encoding another less hydrophobic residue(such as glycine) or a more hydrophobic residue (such as valine,leucine, or isoleucine). Similarly, changes which result in substitutionof one negatively charged residue for another (such as aspartic acid forglutamic acid) or one positively charged residue for another (such aslysine for arginine) can also be expected to produce a functionallyequivalent product. In many cases, nucleotide changes which result inalteration of the N-terminal and C-terminal portions of the proteinmolecule would also not be expected to alter the activity of theprotein.

Each of the proposed modifications is well within the routine skill inthe art, as is determination of retention of biological activity of theencoded products. Moreover, the skilled artisan recognizes thatsubstantially similar sequences are encompassed by the presentinvention. In one embodiment, substantially similar sequences aredefined by their ability to hybridize, under stringent conditions(0.1×SSC, 0.1% SDS, 65° C. and washed with 2×SSC, 0.1% SDS followed by0.1×SSC, 0.1% SDS, 65° C.) with the sequences exemplified herein. In oneembodiment, the present invention includes enzymes having perhydrolaseactivity encoded by isolated nucleic acid molecules that hybridize understringent conditions to the nucleic acid molecules reported herein. In apreferred embodiment, the present invention includes an enzyme havingperhydrolase activity encoded by isolated nucleic acid molecule thathybridizes under stringent conditions to a nucleic acid molecule havinga nucleic acid sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO: 9, SEQ ID NO: 13, and SEQ ID NO: 15.

As used herein, a nucleic acid molecule is “hybridizable” to anothernucleic acid molecule, such as a cDNA, genomic DNA, or RNA, when asingle strand of the first molecule can anneal to the other moleculeunder appropriate conditions of temperature and solution ionic strength.Hybridization and washing conditions are well known and exemplified inSambrook, J. and Russell, D., T. Molecular Cloning: A Laboratory Manual,Third Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor(2001). The conditions of temperature and ionic strength determine the“stringency” of the hybridization. Stringency conditions can be adjustedto screen for moderately similar molecules, such as homologous sequencesfrom distantly related organisms, to highly similar molecules, such asgenes that duplicate functional enzymes from closely related organisms.Post-hybridization washes typically determine stringency conditions. Oneset of preferred conditions uses a series of washes starting with 6×SSC,0.5% SDS at room temperature for 15 min, then repeated with 2×SSC, 0.5%SDS at 45° C. for 30 min, and then repeated twice with 0.2×SSC, 0.5% SDSat 50° C. for 30 min. A more preferred set of conditions uses highertemperatures in which the washes are identical to those above except forthe temperature of the final two 30 min washes in 0.2×SSC, 0.5% SDS wasincreased to 60° C. Another preferred set of stringent hybridizationconditions is 0.1×SSC, 0.1% SDS, 65° C. and washed with 2×SSC, 0.1% SDSfollowed by a final wash of 0.1×SSC, 0.1% SDS, 65° C. with the sequencesexemplified herein.

Hybridization requires that the two nucleic acids contain complementarysequences, although depending on the stringency of the hybridization,mismatches between bases are possible. The appropriate stringency forhybridizing nucleic acids depends on the length of the nucleic acids andthe degree of complementation, variables well known in the art. Thegreater the degree of similarity or homology between two nucleotidesequences, the greater the value of Tm for hybrids of nucleic acidshaving those sequences. The relative stability (corresponding to higherTm) of nucleic acid hybridizations decreases in the following order:RNA:RNA, DNA:RNA, DNA:DNA. For hybrids of greater than 100 nucleotidesin length, equations for calculating Tm have been derived (Sambrook andRussell, supra). For hybridizations with shorter nucleic acids, i.e.,oligonucleotides, the position of mismatches becomes more important, andthe length of the oligonucleotide determines its specificity (Sambrookand Russell, supra). In one aspect, the length for a hybridizablenucleic acid is at least about 10 nucleotides. Preferably, a minimumlength for a hybridizable nucleic acid is at least about 15 nucleotidesin length, more preferably at least about 20 nucleotides in length, evenmore preferably at least 30 nucleotides in length, even more preferablyat least 300 nucleotides in length, and most preferably at least 800nucleotides in length. Furthermore, the skilled artisan will recognizethat the temperature and wash solution salt concentration may beadjusted as necessary according to factors such as length of the probe.

As used herein, the term “percent identity” is a relationship betweentwo or more polypeptide sequences or two or more polynucleotidesequences, as determined by comparing the sequences. In the art,“identity” also means the degree of sequence relatedness betweenpolypeptide or polynucleotide sequences, as the case may be, asdetermined by the match between strings of such sequences. “Identity”and “similarity” can be readily calculated by known methods, includingbut not limited to those described in: Computational Molecular Biology(Lesk, A. M., ed.) Oxford University Press, NY (1988); Biocomputing:Informatics and Genome Projects (Smith, D. W., ed.) Academic Press, NY(1993); Computer Analysis of Sequence Data, Part I (Griffin, A. M., andGriffin, H. G., eds.) Humana Press, NJ (1994); Sequence Analysis inMolecular Biology (von Heinje, G., ed.) Academic Press (1987); andSequence Analysis Primer (Gribskov, M. and Devereux, J., eds.) StocktonPress, NY (1991). Methods to determine identity and similarity arecodified in publicly available computer programs. Sequence alignmentsand percent identity calculations may be performed using the Megalignprogram of the LASERGENE bioinformatics computing suite (DNASTAR Inc.,Madison, Wis.), the AlignX program of Vector NTI v.7.0 (Informax, Inc.,Bethesda, Md.), or the EMBOSS Open Software Suite (EMBL-EBI; Rice et al,Trends in Genetics 16, (6) pp 276-277 (2000)). Multiple alignment of thesequences can be performed using the Clustal method (i.e., CLUSTALW; forexample version 1.83) of alignment (Higgins and Sharp, CABIOS, 5:151-153(1989); Higgins et al., Nucleic Acids Res., 22:4673-4680 (1994); andChenna et al, Nucleic Acids Res., 31 (13):3497-500 (2003)), availablefrom the European Molecular Biology Laboratory via the EuropeanBioinformatics Institute) with the default parameters. Suitableparameters for CLUSTALW protein alignments include GAP Existencepenalty=15, GAP extension=0.2, matrix=Gonnet (e.g., Gonnet250), proteinENDGAP=−1, Protein GAPDIST=4, and KTUPLE=1. In one embodiment, a fast orslow alignment is used with the default settings where a slow alignmentis preferred. Alternatively, the parameters using the CLUSTALW method(version 1.83) may be modified to also use KTUPLE=1, GAP PENALTY=10, GAPextension=−1, matrix=BLOSUM (e.g. BLOSUM64), WTNDOW=5, and TOP DIAGONALSSAVED=5.

In one aspect of the present invention, suitable isolated nucleic acidmolecules (isolated polynucleotides of the present invention) encode apolypeptide having an amino acid sequence that is at least about 30%,preferably at least 33%, preferably at least 40%, preferably at least50%, preferably at least 60%, more preferably at least 70%, morepreferably at least 80%, even more preferably at least 85%, even morepreferably at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%identical to the amino acid sequences reported herein. Suitable nucleicacid molecules of the present invention not only have the abovehomologies, but also typically encode a polypeptide having about 300 toabout 340 amino acids, more preferably about 310 to about 330 aminoacids, and most preferably about 318 amino acids.

As used herein, the terms “signature motif”, “CE-7 signature motif”, and“diagnostic motif” refer to conserved structures shared among a familyof enzymes having a defined activity. The signature motif can be used todefine and/or identify the family of structurally related enzymes havingsimilar enzymatic activity for a defined family of substrates. Thesignature motif can be a single contiguous amino acid sequence or acollection of discontiguous, conserved motifs that together form thesignature motif. Typically, the conserved motif(s) is represented by anamino acid sequence. As described herein, the present perhydrolasesbelong to the family of CE-7 carbohydrate esterases. This family ofenzymes can be defined by the presence of a signature motif (Vincent etal., supra).

As used herein, “codon degeneracy” refers to the nature of the geneticcode permitting variation of the nucleotide sequence without affectingthe amino acid sequence of an encoded polypeptide. Accordingly, thepresent invention relates to any nucleic acid molecule that encodes allor a substantial portion of the amino acid sequences encoding thepresent microbial polypeptide. The skilled artisan is well aware of the“codon-bias” exhibited by a specific host cell in usage of nucleotidecodons to specify a given amino acid. Therefore, when synthesizing agene for improved expression in a host cell, it is desirable to designthe gene such that its frequency of codon usage approaches the frequencyof preferred codon usage of the host cell.

As used herein, “synthetic genes” can be assembled from oligonucleotidebuilding blocks that are chemically synthesized using procedures knownto those skilled in the art. These building blocks are ligated andannealed to form gene segments that are then enzymatically assembled toconstruct the entire gene. “Chemically synthesized”, as pertaining to aDNA sequence, means that the component nucleotides were assembled invitro. Manual chemical synthesis of DNA may be accomplished usingwell-established procedures, or automated chemical synthesis can beperformed using one of a number of commercially available machines.Accordingly, the genes can be tailored for optimal gene expression basedon optimization of nucleotide sequences to reflect the codon bias of thehost cell. The skilled artisan appreciates the likelihood of successfulgene expression if codon usage is biased towards those codons favored bythe host. Determination of preferred codons can be based on a survey ofgenes derived from the host cell where sequence information isavailable.

As used herein, “gene” refers to a nucleic acid molecule that expressesa specific protein, including regulatory sequences preceding (5′non-coding sequences) and following (3′ non-coding sequences) the codingsequence. “Native gene” refers to a gene as found in nature with its ownregulatory sequences, “Chimeric gene” refers to any gene that is not anative gene, comprising regulatory and coding sequences that are notfound together in nature. Accordingly, a chimeric gene may compriseregulatory sequences and coding sequences that are derived fromdifferent sources, or regulatory sequences and coding sequences derivedfrom the same source, but arranged in a manner different from that foundin nature. “Endogenous gene” refers to a native gene in its naturallocation in the genome of an organism. A “foreign” gene refers to a genenot normally found in the host organism, but that is introduced into thehost organism by gene transfer. Foreign genes can comprise native genesinserted into a non-native organism, or chimeric genes. A “transgene” isa gene that has been introduced into the genome by a transformationprocedure.

As used herein, “coding sequence” refers to a DNA sequence that codesfor a specific amino acid sequence. “Suitable regulatory sequences”refer to nucleotide sequences located upstream (5′ non-codingsequences), within, or downstream (3′ non-coding sequences) of a codingsequence, and which influence the transcription, RNA processing orstability, or translation of the associated coding sequence. Regulatorysequences may include promoters, translation leader sequences, RNAprocessing site, effector binding site and stem-loop structure.

As used herein, “promoter” refers to a DNA sequence capable ofcontrolling the expression of a coding sequence or functional RNA. Ingeneral, a coding sequence is located 3′ to a promoter sequence.Promoters may be derived in their entirety from a native gene, or becomposed of different elements derived from different promoters found innature, or even comprise synthetic DNA segments. It is understood bythose skilled in the art that different promoters may direct theexpression of a gene at different stages of development, or in responseto different environmental or physiological conditions. Promoters thatcause a gene to be expressed at most times are commonly referred to as“constitutive promoters”. It is further recognized that since in mostcases the exact boundaries of regulatory sequences have not beencompletely defined, DNA fragments of different lengths may haveidentical promoter activity.

As used herein, the “3′ non-coding sequences” refer to DNA sequenceslocated downstream of a coding sequence and include polyadenylationrecognition sequences (normally limited to eukaryotes) and othersequences encoding regulatory signals capable of affecting mRNAprocessing or gene expression. The polyadenylation signal is usuallycharacterized by affecting the addition of polyadenylic acid tracts(normally limited to eukaryotes) to the 3′ end of the mRNA precursor.

As used herein, the term “operably linked” refers to the association ofnucleic acid sequences on a single nucleic acid molecule so that thefunction of one is affected by the other. For example, a promoter isoperably linked with a coding sequence when it is capable of affectingthe expression of that coding sequence, i.e., that the coding sequenceis under the transcriptional control of the promoter. Coding sequencescan be operably linked to regulatory sequences in sense or antisenseorientation.

As used herein, the term “expression” refers to the transcription andstable accumulation of sense (mRNA) or antisense RNA derived from thenucleic acid molecule described herein. Expression may also refer totranslation of mRNA into a polypeptide.

As used herein, “transformation” refers to the transfer of a nucleicacid molecule into the genome of a host organism, resulting ingenetically stable inheritance. In the present invention, the hostcell's genome includes chromosomal and extrachromosomal (e.g. plasmid)genes. Host organisms containing the transformed nucleic acid moleculesare referred to as “transgenic” or “recombinant” or “transformed”organisms.

As used herein, the terms “plasmid”, “vector” and “cassette” refer to anextrachromosomal element often carrying genes which are not part of thecentral metabolism of the cell, and usually in the form of circulardouble-stranded DNA molecules. Such elements may be autonomouslyreplicating sequences, genome integrating sequences, phage or nucleotidesequences, linear or circular, of a single- or double-stranded DNA orRNA, derived from any source, in which a number of nucleotide sequenceshave been joined or recombined into a unique construction which iscapable of introducing a promoter fragment and DNA sequence for aselected gene product along with appropriate 3′ untranslated sequenceinto a cell. “Transformation cassette” refers to a specific vectorcontaining a foreign gene and having elements in addition to the foreigngene that facilitate transformation of a particular host cell.“Expression cassette” refers to a specific vector containing a foreigngene and having elements in addition to the foreign gene that allow forenhanced expression of that gene in a foreign host.

As used herein, the term “sequence analysis software” refers to anycomputer algorithm or software program that is useful for the analysisof nucleotide or amino acid sequences. “Sequence analysis software” maybe commercially available or independently developed. Typical sequenceanalysis software will include, but is not limited to, the GCG suite ofprograms (Wisconsin Package Version 9.0, Genetics Computer Group (GCG),Madison, Wis.), BLASTP, BLASTN, BLASTX (Altschul et al., J. Mol. Biol.215:403-410 (1990), and DNASTAR (DNASTAR, Inc. 1228 S. Park St. Madison,Wis. 53715 USA), CLUSTALW (for example, version 1.83; Thompson et al.,Nucleic Acids Research, 22(22):4673-4680 (1994), and the FASTA programincorporating the Smith-Waterman algorithm (W. R. Pearson, Comput.Methods Genome Res., [Proc. Int. Symp.] (1994), Meeting Date 1992,111-20. Editor(s): Suhai, Sandor. Publisher: Plenum, New York, N.Y.),Vector NTI (Informax, Bethesda, Md.) and Sequencher v.4.05. Within thecontext of this application it will be understood that where sequenceanalysis software is used for analysis, that the results of the analysiswill be based on the “default values” of the program referenced, unlessotherwise specified. As used herein “default values” will mean any setof values or parameters set by the software manufacturer that originallyload with the software when first initialized.

As used herein, the term “biological contaminants” refers to one or moreunwanted and/or pathogenic biological entities including, but notlimited to, microorganisms, spores, viruses, prions, and mixturesthereof. The process produces an efficacious concentration of at leastone percarboxylic acid useful to reduce and/or eliminate the presence ofthe viable biological contaminants. In a preferred embodiment, themicrobial contaminant is a viable pathogenic microorganism.

As used herein, the term “disinfect” refers to the process ofdestruction of or prevention of the growth of biological contaminants.As used herein, the term “disinfectant” refers to an agent thatdisinfects by destroying, neutralizing, or inhibiting the growth ofbiological contaminants. Typically, disinfectants are used to treatinanimate objects or surfaces. As used herein, the term “antiseptic”refers to a chemical agent that inhibits the growth of disease-carryingmicroorganisms. In one aspect of the embodiment, the biologicalcontaminants are pathogenic microorganisms.

As used herein, the term “virucide” refers to an agent that inhibits ordestroys viruses, and is synonymous with “viricide”. An agent thatexhibits the ability to inhibit or destroy viruses is described ashaving “virucidal” activity. Peracids can have virucidal activity.Typical alternative virucides known in the art which may be suitable foruse with the present invention include, for example, alcohols, ethers,chloroform, formaldehyde, phenols, beta propiolactone, iodine, chlorine,mercury salts, hydroxylamine, ethylene oxide, ethylene glycol,quaternary ammonium compounds, enzymes, and detergents.

As used herein, the term “biocide” refers to a chemical agent, typicallybroad spectrum, which inactivates or destroys microorganisms. A chemicalagent that exhibits the ability to inactivate or destroy microorganismsis described as having “biocidal” activity. Peracids can have biocidalactivity. Typical alternative biocides known in the art, which may besuitable for use in the present invention include, for example,chlorine, chlorine dioxide, chloroisocyanurates, hypochlorites, ozone,acrolein, amines, chlorinated phenolics, copper salts, organo-sulphurcompounds, and quaternary ammonium salts.

As used herein, the phrase “minimum biocidal concentration” refers tothe minimum concentration of a biocidal agent that, for a specificcontact time, will produce a desired lethal, irreversible reduction inthe viable population of the targeted microorganisms. The effectivenesscan be measured by the logio reduction in viable microorganisms aftertreatment. In one aspect, the targeted reduction in viablemicroorganisms after treatment is at least a 3-log reduction, morepreferably at least a 4-log reduction, and most preferably at least a5-log reduction. In another aspect, the minimum biocidal concentrationis at least a 6-log reduction in viable microbial cells.

As used herein, the terms “peroxygen source” and “source of peroxygen”refer to compounds capable of providing hydrogen peroxide at aconcentration of about 1 mM or more when in an aqueous solutionincluding, but not limited to, hydrogen peroxide, hydrogen peroxideadducts (e.g., urea-hydrogen peroxide adduct (carbamide peroxide)),perborates, and percarbonates. As described herein, the concentration ofthe hydrogen peroxide provided by the peroxygen compound in the aqueousreaction mixture is initially at least 1 mM or more upon combining thereaction components. In one embodiment, the hydrogen peroxideconcentration in the aqueous reaction mixture is at least 10 mM. Inanother embodiment, the hydrogen peroxide concentration in the aqueousreaction mixture is at least 100 mM. In another embodiment, the hydrogenperoxide concentration in the aqueous reaction mixture is at least 200mM. In another embodiment, the hydrogen peroxide concentration in theaqueous reaction mixture is 500 mM or more. In yet another embodiment,the hydrogen peroxide concentration in the aqueous reaction mixture is1000 mM or more. The molar ratio of the hydrogen peroxide to enzymesubstrate, e.g. triglyceride, (H₂O₂:substrate) in the aqueous reactionmixture may be from about 0.002 to 20, preferably about 0.1 to 10, andmost preferably about 0.5 to 5. Alternatively, a peroxygen source (e.g.,hydrogen peroxide) can be generated in situ by the reaction of asubstrate and oxygen catalyzed by an enzyme having oxidase activity(e.g., glucose oxidase, alcohol oxidase, monoamine oxidase, lactateoxidase, amino acid oxidase).

Suitable Reaction Conditions for Controlling the Enzyme-CatalyzedPreparation of Peracids from Carboxylic Acid Esters and HydrogenPeroxide

In one aspect, a process is provided to produce an aqueous mixturecomprising a target concentration of peracid by reacting carboxylic acidesters and an inorganic peroxide, not limited to hydrogen peroxide,sodium perborate or sodium percarbonate, in the presence of an enzymecatalyst having pH-sensitive perhydrolysis activity. In one embodiment,the enzyme catalyst comprises a perhydrolase having a structurebelonging to the CE-7 carbohydrate esterase family. In anotherembodiment, the perhydrolase catalyst is structurally classified as acephalosporin C deacetylase. In another embodiment, the perhydrolasecatalyst is structurally classified as an acetyl xylan esterase.

In one embodiment, the perhydrolase catalyst comprises an enzyme havinga CE-7signature motif that aligns with a reference sequence SEQ ID NO: 2using CLUSTALW, said signature motif comprising:

-   -   i) an RGQ motif at amino acid positions 118-120 of SEQ ID NO:2;    -   ii) a GXSQG motif at amino acid positions 179-183 of SEQ ID        NO:2; and    -   iii) an HE motif at amino acid positions 298-299 of SEQ ID NO:2;    -   wherein said enzyme also comprises at least 30% amino acid        identity to SEQ ID NO: 2.

In a further embodiment, the signature motif additional comprises aforth conserved motif defined as an LXD motif at amino acid residues267-269 when aligned to reference sequence SEQ ID NO: 2 using CLUSTALW.

In another embodiment, the perhydrolase catalyst comprises an enzymehaving an amino acid sequence selected from the group consisting of SEQID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10, SEQID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 20,SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 30, SEQ ID NO: 54, SEQ ID NO:56, SEQ ID NO: 58, SEQ ID NO: 60, and SEQ ID NO: 62, or a substantiallysimilar enzyme having perhydrolase activity derived by substituting,deleting or adding one or more amino acids to said amino acid sequence.

In another embodiment, a substantially similar enzyme having an aminoacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% identical to one or more amino acid sequences selected fromthe group consisting of SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ IDNO: 8, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, SEQID NO: 18, SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO; 30,SEQ ID NO: 54, SEQ ID NO: 56, SEQ ID NO: 58, SEQ ID NO: 60, and SEQ IDNO: 62.

In another embodiment, the perhydrolase catalyst comprises an enzymehaving an amino acid sequence encoded by a nucleic acid molecule thathybridizes to a nucleic acid sequence selected from the group consistingof SEQ ID NO: 1; SEQ ID NO: 3; SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 9,SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 17, SEQ ID NO:19, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 29, SEQ ID NO: 55, SEQ IDNO: 57, SEQ ID NO: 59, and SEQ ID NO: 61 under stringent hybridizationconditions.

In another embodiment, the perhydrolase catalyst comprises an enzymehaving at least 30%, preferably at last 36%, amino acid identity to acontiguous signature motif defined as SEQ ID NO: 61 wherein theconserved motifs described above (e.g. RGQ, GXSQG, and HE, andoptionally, LXD) are conserved.

In one embodiment, suitable substrates include esters provided by thefollowing formula:

[X]_(m)R₅

-   -   wherein X=an ester group of the formula R₆C(O)O    -   R₆=C1 to C7 linear, branched or cyclic hydrocarbyl moiety,        optionally substituted with hydroxyl groups or C1 to C4 alkoxy        groups, wherein R₆ optionally comprises one or more ether        linkages for R6=C2 to C7;    -   R₅=a C1 to C6 linear, branched, or cyclic hydrocarbyl moiety        optionally substituted with hydroxyl groups; wherein each carbon        atom in R₅ individually comprises no more than one hydroxyl        group or no more than one ester group; wherein R₅ optionally        comprises one or more ether linkages;    -   m=1 to the number of carbon atoms in R₅; and        -   wherein said esters have a solubility in water of at least 5            ppm at 25° C.

In another embodiment, suitable substrates also include esters of theformula:

wherein R₁=C1 to C7 straight chain or branched chain alkyl optionallysubstituted with an hydroxyl or a C1 to C4 alkoxy group and R₂=C1 to C10straight chain or branched chain alkyl, alkenyl, alkynyl, aryl,alkylaryl, alkylheteroaryl, heteroaryl, (CH₂CH₂—O)_(n)H or(CH₂CH(CH₃)—O)_(n)H and n=1 to 10.

In another embodiment, suitable substrates include glycerides of theformula:

wherein R₁=C1 to C7 straight chain or branched chain alkyl optionallysubstituted with an hydroxyl or a C1 to C4 alkoxy group and R₃ and R₄are individually H or R₁C(O).

In another embodiment, R₆ is C1 to C7 linear hydrocarbyl moiety,optionally substituted with hydroxyl groups or C1 to C4 alkoxy groups,optionally comprising one or more ether linkages. In a further preferredembodiment, R₆ is C2 to C7 linear hydrocarbyl moiety, optionallysubstituted with hydroxyl groups, and/or optionally comprising one ormore ether linkages.

In another embodiment, suitable substrates also include acetylatedsaccharides selected from the group consisting of acetylated mono-, di-,and polysaccharides. In a preferred embodiment, the acetylatedsaccharides include acetylated mono- , di-, and polysaccharides. Inanother embodiment, the acetylated saccharides are selected from thegroup consisting of acetylated xylan, fragments of acetylated xylan,acetylated xylose(such as xylose tetraacetate), acetylated glucose (suchas glucose pentaacetate), β-D-ribofuranose-1,2,3,5-tetraacetate,tri-O-acetyl-D-galactal, and tri-O-acetyl-D-glucal, and acetylatedcellulose. In a preferred embodiment, the acetylated saccharide isselected from the group consisting ofβ-D-ribofuranose-1,2,3,5-tetraacetate, tri-O-acetyl-D-galactal, andtri-O-acetyl-D-glucal, and acetylated cellulose. As such, acetylatedcarbohydrates may be suitable substrates for generating percarboxylicacids using the present process (i.e., in the presence of a peroxygensource).

In one embodiment, the substrate is selected from the group consistingof: monoacetin; diacetin; triacetin; monopropionin; dipropionin;tripropionin; monobutyrin; dibutyrin; tributyrin; glucose pentaacetate;xylose tetraacetate; acetylated xylan; acetylated xylan fragments;β-D-ribofuranose-1,2,3,5-tetraacetate; tri-O-acetyl-D-galactal;tri-O-acetyl-glucal; monoesters or diesters of 1,2-ethanediol,1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol,2,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 2,5-pentanediol,1,6-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 1,6-hexanediol; andmixtures thereof.

In a preferred embodiment, the substrate is selected from the groupconsisting of ethyl acetate, methyl lactate, ethyl lactate, methylglycolate, ethyl glycol ate, methyl methoxyacetate, ethylmethoxyacetate, methyl 3-hydroxybutyrate, ethyl 3-hydroxybutyrate,triethyl 2-acetyI citrate, glucose pentaacetate, gluconolactone,glycerides (mono-, di-, and triglycerides) such as monoacetin, diacetin,triacetin, monopropionin, dipropionin (glyceryl dipropionate),tripropionin (1,2,3-tripropionylglycerol), monobutyrin, dibutyrin(glyceryl dibutyrate), tributyrin (1,2,3-tributyrylglycerol), acetylatedsaccharides, and mixtures thereof.

In a further preferred aspect, the carboxylic acid ester substrates areselected from the group consisting of monoacetin, diacetin, triacetin,monopropionin, dipropionin, tripropionin, monobutyrin, dibutyrin,tributyrin, ethyl acetate, and ethyl lactate. In yet another aspect, thecarboxylic acid ester substrates are selected from the group consistingof diacetin, triacetin, ethyl acetate, and ethyl lactate. In a preferredaspect, the carboxylic acid ester is a glyceride selected from the groupconsisting of monoacetin, diacetin, triacetin, and mixtures thereof.

The carboxylic acid ester is present in the reaction mixture at aconcentration sufficient to produce the desired concentration of peracidupon enzyme-catalyzed perhydrolysis. The carboxylic acid ester need notbe completely soluble in the reaction mixture, but has sufficientsolubility to permit conversion of the ester by the perhydrolasecatalyst to the corresponding peracid. The carboxylic acid ester ispresent in the reaction mixture at a concentration of 0.0005 wt % to 40wt % of the reaction mixture, preferably at a concentration of 0.1 wt %to 20 wt % of the reaction mixture, and more preferably at aconcentration of 0.5 wt % to 10 wt % of the reaction mixture. The wt %of carboxylic acid ester may optionally be greater than the solubilitylimit of the carboxylic acid ester, such that the concentration of thecarboxylic acid ester is at least 0.0005 wt % in the reaction mixturethat is comprised of water, enzyme catalyst, and source of peroxide,where the remainder of the carboxylic acid ester remains as a secondseparate phase of a two-phase aqueous/organic reaction mixture. Not allof the added carboxylic acid ester must immediately dissolve in theaqueous reaction mixture, and after an initial mixing of all reactioncomponents, additional continuous or discontinuous mixing is optional.

The peroxygen source may include, but is not limited to, hydrogenperoxide, hydrogen peroxide adducts (e.g., urea-hydrogen peroxide adduct(carbamide peroxide)) perborate salts and percarbonate salts. Theconcentration of peroxygen compound in the reaction mixture may rangefrom 0.0033 wt % to about 50 wt %, preferably from 0.033 wt % to about40 wt %, more preferably from 0.33 wt % to about 30 wt %.

Many perhydrolase catalysts (whole cells, permeabilized whole cells, andpartially purified whole cell extracts each containing an enzyme havingperhydrolase activity) have been reported to also have one or moreenzymes having catalase activity (EC 1.11.1.6). Catalases catalyze theconversion of hydrogen peroxide into oxygen and water. In one aspect,the perhydrolysis catalyst lacks catalase activity. In another aspect, acatalase inhibitor is added to the reaction mixture. Examples ofcatalase inhibitors include, but are not limited to, sodium azide andhydroxylamine sulfate. One of skill in the art can adjust theconcentration of catalase inhibitor as needed. The concentration of thecatalase inhibitor typically ranges from 0.1 mM to about 1 M; preferablyabout 3 mM to about 50 mM; more preferably from about 1 mM to about 20mM. In one aspect, sodium azide concentration typically ranges fromabout 20 mM to about 60 mM while hydroxylamine sulfate is concentrationis typically about 0.5 mM to about 30 mM, preferably about 10 mM.

In another embodiment, the perhydrolase catalyst lacks significantcatalase activity or is engineered to decrease or eliminate catalaseactivity. The catalase activity in a host cell can be down-regulated oreliminated by disrupting expression of the gene(s) responsible for thecatalase activity using well known techniques including, but not limitedto, transposon mutagenesis, RNA antisense expression, targetedmutagenesis, and random mutagenesis. In a preferred embodiment, thegene(s) encoding the endogenous catalase activity are down-regulated ordisrupted (i.e. knocked-out). As used herein, a “disrupted” gene is onewhere the activity and/or function of the protein encoded by themodified gene is no longer present. Means to disrupt a gene arewell-known in the art and may include, but are not limited toinsertions, deletions, or mutations to the gene so long as the activityand/or function of the corresponding protein is no longer present. In afurther preferred embodiment, the production host is an E. coliproduction host comprising a disrupted catalase gene selected from thegroup consisting of katG (SEQ ID NO: 40) and katE (SEQ ID NO: 49). Inanother embodiment, the production host is an E. coli strain comprisinga down-regulation and/or disruption in both katg1 and a katE catalasegenes. An E. coli strain comprising a double-knockout of katG and katEis provided herein (see Example 3; E. coli strain KLP18).

The catalase negative E. coli strain KLP18 (katG and katE doubleknockout) that was constructed (Example 3) was demonstrated to be asuperior host for large scale (10-L and greater) production ofperhydrolase enzymes compared to the catalase negative strain UM2 (E.coli Genetic Stock Center #7156, Yale University, New Haven Conn.), asdetermined by growth under fermenter conditions. Although both KLP18 andUM2 are catalase-negative strains, UM2 is known to have numerousnutritional auxotrophies, and therefore requires media that is enrichedwith yeast extract and peptone. Even when employing enriched media forfermentation, UM2 grew poorly and to a limited maximum cell density(OD). In contrast, KLP18 had no special nutritional requirements andgrew to high cell densities on mineral media alone or with additionalyeast extract.

The concentration of the perhydrolase catalyst in the aqueous reactionmixture depends on the specific catalytic activity of the catalyst, andis chosen to obtain the desired rate of reaction. The weight ofperhydrolase catalyst in perhydrolysis reactions typically ranges from0.0001 mg to 10 mg per mL of total reaction volume, preferably from0.001 mg to 1.0 mg per mL. The catalyst may also be immobilized on asoluble or insoluble support using methods well-known to those skilledin the art; see for example, Immobilization of Enzymes and Cells; GordonF. Bickerstaff Editor; Humana Press, Totowa, N.J., USA; 1997. The use ofimmobilized catalysts permits the recovery and reuse of the catalyst insubsequent reactions. The enzyme catalyst may be in the form of wholemicrobial cells, permeabilized microbial cells, microbial cell extracts,partially-purified or purified enzymes, and mixtures thereof.

In one aspect, the concentration of peracid generated by the combinationof chemical perhydrolysis and enzymatic perhydrolysis of the carboxylicacid ester is sufficient to provide an effective concentration ofperacid for bleaching or disinfection at a desired pH. In anotheraspect, the present methods provide combinations of enzymes and enzymesubstrates to produce the desired effective concentration of peracid,where, in the absence of added enzyme, there is a significantly lowerconcentration of peracid produced. Although there may in some cases besubstantial chemical perhydrolysis of the enzyme substrate by directchemical reaction of inorganic peroxide with the enzyme substrate, theremay not be a sufficient concentration of peracid generated to provide aneffective concentration of peracid in the desired applications, and asignificant increase in total peracid concentration is achieved by theaddition of an appropriate perhydrolase catalyst to the reactionmixture.

Peracids can be corrosive to certain metal surfaces, caustic to users,or otherwise destructive, so it may be desirable to limit the totalamount of peracid produced during the reaction to prevent or minimizeits corrosive effect. For example, applications that require productionof no more than about 100 to about 1000 ppm of peracid in about 1 minuteto about 5 minutes often employ reaction conditions that yield a finalconcentration of peracid well above this limit. In such instances it canbe desirable to regulate the amount of peracid produced and, in somecases, to regulate the rate at which the peracid is produced.

As described herein, an aqueous reaction mixture can produce a limitedamount of peracid if the proper reaction conditions are used. Onecomponent of the reaction mixture that can be important in this regardis a buffer, specifically the pKa and concentration of the buffer. Thesecharacteristics of the buffer can regulate the pH of the reactionmixture as peracids are produced, and where byproduct carboxylic acidsmay also be produced by the enzyme-catalyzed hydrolysis of peracid tocarboxylic acid and hydrogen peroxide; therefore, selecting a bufferwith the proper characteristics is one way to control, or inactivate,the catalytic activity of a pH-sensitive enzyme catalyst in order toproduce a target concentration of peracid. The buffer may be any buffersuitable for carrying out an enzymatic perhydrolysis reaction at thedesired pH. In some aspects, the buffer is selected from the groupconsisting of the sodium salt, the potassium salt or mixed sodium andpotassium salts of bicarbonate buffer, citrate buffer, methylphosphonatebuffer, pyrophosphate buffer and phosphate buffer. In some aspects, thebuffer is bicarbonate buffer or citrate buffer. In some aspects, theaqueous reaction mixture having a specific initial pH includes a buffer.

One way to control the amount of peracid produced by an enzyme-drivenreaction is to use reaction conditions that selectively reduce, orinactivate, the catalytic function of the enzyme. Accordingly, theinitial pH of the reaction mixture may be adjusted such that the pH ofthe reaction falls as peracid is produced, ultimately resulting in thereaction mixture having a pH that prevents efficient, or substantial,enzyme activity. In one embodiment, the initial pH of the reactionmixture is about 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0,6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4,7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, or about 8.5.

In some aspects, the buffer included in the aqueous reaction mixture canestablish the initial pH of the reaction mixture. In some aspects, thebuffer produces an aqueous reaction mixture with an initial pH of about4.0 to about 10.0. In some aspects, the buffer produces an aqueousreaction mixture with an initial pH of about 5.0 to about 9.0. In someaspects, the buffer produces an aqueous reaction mixture with an initialpH of about 6.0 to about 8.5. In some aspects, the buffer produces anaqueous reaction mixture with an initial pH of about 5.0, 5.1, 5.2, 5.3,5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7,6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1,8.2, 8.3, 8.4, or about 8.5. In some aspects, the reaction mixturecontaining a buffer has an initial pH of about 8.1. In some aspects, thebuffer in a reaction mixture having an initial pH of about 8.1 isbicarbonate buffer. In some aspects, the reaction mixture containing abuffer has an initial pH of about 7.2. In some aspects, the buffer in areaction mixture having an initial pH of about 7.2 is citrate buffer. Insome aspects, the buffer in a reaction mixture having an initial pH ofabout 7.2 is bicarbonate buffer. In some aspects, the buffer in areaction mixture having an initial pH of about 7.2 is phosphate buffer.In some aspects, the reaction mixture containing a buffer has an initialpH of about 6.5. In some aspects, the buffer in a reaction mixturehaving an initial pH of about 6.5 is citrate buffer. In some aspects,the buffer in a reaction mixture having an initial pH of about 6.5 isbicarbonate buffer. In some aspects, the buffer in a reaction mixturehaving an initial pH of about 6.5 is phosphate buffer. In some aspects,the reaction mixture containing a buffer has an initial pH of about 6.0.In some aspects, the buffer in a reaction mixture having an initial pHof about 6.0 is citrate buffer. In some aspects, the buffer in areaction mixture having an initial pH of about 6.0 is bicarbonatebuffer. In some aspects, the buffer in a reaction mixture having aninitial pH of about 6.0 is phosphate buffer. In some aspects, thereaction mixture containing a buffer has an initial pH of about 5.5. Insome aspects, the buffer in a reaction mixture having an initial pH ofabout 5.5 is citrate buffer. In some aspects, the buffer in a reactionmixture having an initial pH of about 5.5 is bicarbonate buffer.

As described herein, an aqueous reaction mixture can produce a limitedamount of peracid if the proper reaction conditions are used. One aspectof the reaction mixture that can be important in this regard is bufferconcentration. For example, a dilute buffer has limited capacity tobuffer the reaction mixture as peracid is produced, thereby reducing thepH of the reaction mixture and reducing, or inactivating, enzymeactivity. The concentration of the buffer can regulate the pH of thereaction mixture as peracids are produced; therefore, selecting a bufferwith the proper concentration is one way to control, or inactivate, thecatalytic activity of a pH-sensitive enzyme catalyst to produce a targetconcentration of peracid. Accordingly, in some aspects, the aqueousreaction mixture includes a buffer having a specific concentration. Thebuffer may be any buffer suitable for carrying out an enzymaticperhydrolysis reaction. In some aspects, the buffer is selected from thegroup consisting of, but not limited to, the sodium salt, potassiumsalt, or mixture of sodium and potassium salts of bicarbonate buffer,citrate buffer, acetate buffer, phosphate buffer, pyrophosphate bufferand methylphosphonate buffer. In some aspects, the buffer is sodiumbicarbonate buffer or sodium citrate buffer. In some aspects, the bufferhas a concentration of about 0.01 mM to about 200 mM. In some aspects,the buffer has a concentration of about 0.01 mM to about 100 mM. In someaspects, the buffer has a concentration of about 0.01 mM to about 50 mMIn some aspects, the buffer has a concentration of about 100, 95, 90,85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, 5 2.5,1, 0.5, or about 0.1 mM. In some aspects, the buffer has a concentrationof about 50 mM. In some aspects, the buffer having an initialconcentration of about 50 mM is citrate buffer. In some aspects, thebuffer having an initial concentration of about 50 mM is bicarbonatebuffer. In some aspects, the buffer has a concentration of about 25 mMto about 1 mM. In some aspects, the buffer having an initialconcentration of about 25 mM to about 1 mM is citrate buffer. In someaspects, the buffer having an initial concentration of about 25 mM toabout 1 mM is bicarbonate buffer.

The amount of peracid produced by an enzyme-driven reaction can also beregulated by selecting a reaction mixture initial pH and a buffer with apKa that will cause the pH of the reaction mixture to fall such that theenzymatic activity of the reaction is reduced or inactivated once thedesired concentration of peracid is produced. In one aspect, the initialpH of the reaction mixture is about 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6,5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0,7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, orabout 8.5 and the pKa of the buffer is about 5.0, 5.1, 5.2, 5.3, 5.4,5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6,7, 6.8,6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0 or about 8.1.

In another embodiment, an enzyme catalyst sensitive to acidic pH wherethe enzyme activity decreases significantly with decreasing pH, could beused to control an enzyme-catalyzed reaction because the production ofperacid would cause the pH of the reaction mixture to fall to a point atwhich catalytic activity would be reduced significantly or inactivated.In reactions where the enzyme activity may also catalyze the hydrolysisof peracid to carboxylic acid and hydrogen peroxide, the production ofcarboxylic acid may also cause the pH of the reaction mixture to fall toa point at which catalytic activity would be reduced significantly orinactivated. For example, in one embodiment, total protein extract fromB. subtilis ATCC® 31954™ could be used as a catalyst. In anotherembodiment, a particular enzyme from B. subtilis ATCC® 31954™ havingperhydrolase activity could be used as a catalyst. In one embodiment,total protein extract from B. pumilus could be used as a catalyst. Inanother embodiment, a particular enzyme from B. pumilus havingperhydrolase activity could be used as a catalyst. In one embodiment,total protein extract from T. neapolitana could be used as a catalyst.In another embodiment, a particular protein from T. neapolitana havingperhydrolase activity could be used as a catalyst. In one embodiment,total protein extract from T. maritima could be used as a catalyst. Inanother embodiment, a particular protein from T. maritima havingperhydrolase activity could be used as a catalyst.

The production of peracid in an aqueous reaction mixture can alter theenzymatic activity of an enzyme catalyzing the production of peracid.For example, production of peracid can lower the pH of the reactionmixture, which can reduce or inactivate the activity of an enzymecatalyst. In reactions where the enzyme activity may also catalyze thehydrolysis of peracid to carboxylic acid and hydrogen peroxide, theproduction of carboxylic acid may also cause the pH of the reactionmixture to fall to a point at which catalytic activity would be reducedsignificantly or inactivated. Accordingly, in some aspects, theproduction of peracid or peracid and carboxylic acid reduces theactivity of an enzyme catalyst by about 25% to about 100%. In someaspects, the production of peracid or peracid and carboxylic acidreduces the activity of an enzyme catalyst by about 40% to about 90%. Insome aspects, the production of peracid or peracid and carboxylic acidreduces the activity of an enzyme catalyst by about 60% to about 80%. Insome aspects, the production of peracid or peracid and carboxylic acidreduces the activity of an enzyme catalyst by about 50%, 55%, 60%, 65%,70%, 75%, 80%, 85%, 90%, 95% or about 100%. In some aspects, theproduction of peracid or peracid and carboxylic acid reduces the pH ofthe reaction mixture such that the activity of the enzyme catalyst isreduced by at least about 75%. In some aspects, the production ofperacid or peracid and carboxylic acid reduces the pH of the reactionmixture such that the activity of the enzyme catalyst is reduced by atleast about 85%. The pH of the final reaction mixture containing peracidis from about 2 to about 9. In some embodiments the pH of the finalreaction mixture containing peracid is from about 3 to about 8, morepreferably from about 4 to about 7. In some embodiments the pH of thefinal reaction mixture containing peracid is from about 5 to about 6. Insome embodiments the pH of the final reaction mixture containing peracidis from about 5 to about 5.5. In some embodiments the pH of the finalreaction mixture containing peracid is from about 4.5 to about 5.

The concentration of peracid generated (e.g. peracetic acid) by theperhydrolysis of at least one carboxylic acid ester is at least about 2ppm, preferably at least 20 ppm, more preferably at least 100 ppm, morepreferably at least 200 ppm, more preferably at least 300 ppm, morepreferably at least 500 ppm, more preferably at least 800 ppm, morepreferably at least about 1000 ppm within 10 minutes, preferably within5 minutes, and most preferably within 1 minute of initiating theperhydrolysis reaction. In some aspects, the concentration of peracidgenerated (e.g. peracetic acid) by the perhydrolysis of at least onecarboxylic acid ester is from about 100 ppm to about 1200 ppm, but isnot more that about 2500 ppm, within 10 minutes, preferably within 5minutes, and most preferably within 1 minute of initiating theperhydrolysis reaction. More preferably, the concentration of peracidgenerated by the perhydrolysis of at least one carboxylic acid ester isfrom about 400 ppm to about 600 ppm, within 10 minutes, preferablywithin 5 minutes, and most preferably within 1 minute of initiating theperhydrolysis reaction. The product mixture comprising the peracid maybe optionally diluted with water, or a solution predominantly comprisedof water, to produce a mixture with the desired lower concentration ofperacid. In one aspect, the reaction time required to produce thedesired concentration of peracid is not greater than about two hours,preferably not greater than about 30 minutes, more preferably notgreater than about 10 minutes, even more preferably not greater thanabout 5 minutes, and most preferably in about 1 minute or less. In otheraspects, a hard surface or inanimate object contaminated with aconcentration of a microbial population is contacted with the peracidformed in accordance with the processes described herein within about 1minute to about 168 hours of combining said reaction components, orwithin about 1 minute to about 48 hours, or within about 1 minute to 2hours of combining said reaction components, or any such time intervaltherein.

In an application for in situ generation of peracetic acid fordisinfection of hard surfaces, it can be desirable to rapidly generate asufficient amount of peracid to disinfect a hard surface, withoutsignificantly exceeding the upper efficacious concentration, therebylimiting or preventing the corrosion of the surface. Peracids can beproduced in this manner using enzyme-catalyzed reactions having theappropriate buffer, pH, and enzyme concentrations and using an enzymethat is significantly reduced in activity or inactivated by a decreasein pH. Accordingly, in one aspect, the enzyme-catalyzed reaction mixtureincorporates a catalytic enzyme that loses activity after producing fromabout 500 ppm to about 600 ppm of peracid, due to the acidic pH of thereaction mixture once the desired amount of peracid is produced. Thissort of reaction mixture can be modified in other embodiments to causethe catalytic enzyme to lose activity after the production of from about100 ppm to about 200 ppm of peracid, from about 200 ppm to about 300 ppmof peracid, from about 300 ppm to about 400 ppm of peracid, from about400 ppm to about 500 ppm of peracid, from about 600 ppm to about 700 ppmof peracid, from about 700 to about 800 ppm of peracid, from about 800ppm to about 900 ppm of peracid, from about 900 ppm to about 1000 ppm ofperacid, or from about 100 ppm to about 500 ppm of peracid, from about500 ppm to about 1000 ppm of peracid, or from about 1000 ppm to about2000 ppm of peracid, as needed based on the particular application.

In some aspects, it is also important to produce peracids in a shortperiod of time; however, many of these applications also requireproduction of only a fixed amount of peracid. For example, it can bedesirable for a mixture giving rise to a peracid-based disinfectantsolution to produce only from about 100 ppm to about 1200 ppm of peracidin about 1 minute, such that substantial amounts of peracid are notproduced following the first minute of production. Accordingly, providedherein are enzyme-catalyzed reactions for producing peracids inconcentrations from about 100 ppm to about 1200 ppm are produced inabout 1 minute without significant production of peracids thereafter.

Of course, those of skill in the art will recognize that other reactionconditions relating to pH, pKa, buffer concentration, and catalystactivity/pH sensitivity will provide the means to limit peracidproduction by the methods described herein. Such conditions and usesthereof are within the scope of this disclosure.

Described are aqueous peracid solutions that maintain a relativelystable concentration of peracid, i.e. within about 20% of a targetperacid concentration, after the reduction, or inactivation, of theenzyme-catalyzed production of peracid, and methods for generating suchstable peracid solutions. In one embodiment, the stability of theaqueous reaction product comprising the target concentration of peracidconcentration is measured in a closed system (for example, a reactionchamber or a container made of a material that does not substantiallyreact with (or enhance degradation of) the peroxycarboxylic acidproduced) at room temperature (approximately 21-22° C.). In somepreferred embodiments, the aqueous peracid solutions maintain a peracidconcentration within about 15%, and more preferably within about 10%, ofa target peracid concentration, after the reduction, or inactivation, ofthe enzyme-catalyzed production of peracid. The stability of the peracidconcentration can persist for hours after the reduction, orinactivation, of the enzyme-catalyzed production of peracid. In oneembodiment, the peracid concentration is stable for about 3 hours afterthe enzyme-catalyzed production of peracid is over. In anotherembodiment, the peracid concentration is stable for about 6 hours afterthe enzyme-catalyzed production of peracid is over. In one embodiment,the peracid concentration is stable for about 9 hours after theenzyme-catalyzed production of peracid is over. In one embodiment, theperacid concentration is stable for about 12 hours after theenzyme-catalyzed production of peracid is over. In another embodiment,the peracid concentration is stable for about 15 hours after theenzyme-catalyzed production of peracid is over. In another embodiment,the peracid concentration is stable for about 18 hours after theenzyme-catalyzed production of peracid is over. In one embodiment, theperacid concentration is stable for about 21 hours after theenzyme-catalyzed production of peracid is over. In another embodiment,the peracid concentration is stable for about 24 hours after theenzyme-catalyzed production of peracid is over. In one embodiment, theperacid concentration is stable for about 30 hours after theenzyme-catalyzed production of peracid is over. In one embodiment, theperacid concentration is stable for about 36 hours after theenzyme-catalyzed production of peracid is over. In one embodiment, theperacid concentration is stable for about 42 hours after theenzyme-catalyzed production of peracid is over. In another embodiment,the peracid concentration is stable for about 48 hours after theenzyme-catalyzed production of peracid is over. In one embodiment, theperacid concentration is stable for greater than 48 hours after theenzyme-catalyzed production of peracid is over.

The temperature of the reaction is chosen to control both the reactionrate and the stability of the enzyme catalyst activity. The temperatureof the reaction may range from just above the freezing point of thereaction mixture (approximately 0° C.) to about 75° C., with a preferredrange of reaction temperature of from about 5° C. to about 55° C.

In another aspect, the enzymatic perhydrolysis reaction mixture maycontain an organic solvent that acts as a dispersant to enhance the rateof dissolution of the carboxylic acid ester in the reaction mixture.Such solvents include, but are not limited to, propylene glycol methylether, acetone, cyclohexanone, diethylene glycol butyl ether,tripropylene glycol methyl ether, diethylene glycol methyl ether,propylene glycol butyl ether, dipropylene glycol methyl ether,cyclohexanol, benzyl alcohol, isopropanol, ethanol, propylene glycol,and mixtures thereof.

In another aspect, the enzymatic perhydrolysis product may containadditional components that provide desirable functionality. Theseadditional components include, but are not limited to buffers, detergentbuilders, thickening agents, emulsifiers, surfactants, wetting agents,corrosion inhibitors (e.g., benzotriazole), enzyme stabilizers, andperoxide stabilizers (e.g., metal ion chelating agents). Many of theadditional components are well known in the detergent industry (see, forexample, U.S. Pat. Mo. 5,932,532; hereby incorporated by reference).Examples of emulsifiers include, but are not limited to polyvinylalcohol or polyvinylpyrrolidone. Examples of thickening agents include,but are not limited to LAPONITE® RD, corn starch, PVP, CARBOWAX®,CARBOPOL®, CABOSIL®, polysorbate 20, PVA, and lecithin. Examples ofbuffering systems include, but are not limited to sodium phosphatemonobasic/sodium phosphate dibasic; sulfamic acid/triethanolamine;citric acid/triethanolamine; tartaric acid/triethanolamine; succinicacid/triethanolamine; and acetic acid/triethanolamine. Examples ofsurfactants include, but are not limited to a) non-ionic surfactantssuch as block copolymers of ethylene oxide or propylene oxide,ethoxylated or propoxylated linear and branched primary and secondaryalcohols, and aliphatic phosphine oxides b) cationic surfactants such asquaternary ammonium compounds, particularly quaternary ammoniumcompounds having a C8-C20 alkyl group bound to a nitrogen atomadditionally bound to three C1-C2 alkyl groups, c) anionic surfactantssuch as alkane carboxylic acids (e.g., C8-C20 fatty acids), alkylphosphonates, alkane sulfonates (e.g., sodium dodecylsulphate “SDS”) orlinear or branched alkyl benzene sulfonates, alkene sulfonates and d)amphoteric and zwitterionic surfactants such as aminocarboxylic acids,aminodicarboxylic acids, alkybetaines, and mixtures thereof. Additionalcomponents may include fragrances, dyes, stabilizers of hydrogenperoxide (e.g., metal chelators such as1-hydroxyethylidene-1,1-diphosphonic acid (DEQUEST® 2010, Solutia Inc.,St. Louis, Mo. and ethylenediaminetetraacetic acid (EDTA)), TURPINAL®SL, DEQUEST® 0520, DEQUEST® 0531, stabilizers of enzyme activity (e.g.,polyethyleneglycol (PEG)), and detergent builders.

In another aspect, the enzymatic perhydrolysis product may be pre-mixedto generate the desired concentration of peroxycarboxylic acid prior tocontacting the surface or inanimate object to be disinfected.

In another aspect, the enzymatic perhydrolysis product is not pre-mixedto generate the desired concentration of peroxycarboxylic acid prior tocontacting the surface or inanimate object to be disinfected, butinstead, the components of the reaction mixture that generate thedesired concentration of percarboxylic acid are contacted with thesurface or inanimate object to be disinfected, generating the desiredconcentration of peroxycarboxylic acid. In some embodiments, thecomponents of the reaction mixture combine or mix at the locus. In someembodiments, the reaction components are delivered or applied to thelocus and subsequently mix or combine to generate the desiredconcentration of peroxycarboxylic acid.

In Situ Production of Peracids Using a Perhydrolase Catalyst

Cephalosporin C deacetylases (E.C. 3.1.1.41; systematic namecephalosporin C acetylhydrolases; CAHs) are enzymes having the abilityto hydrolyze the acetyl ester bond on cephalosporins such ascephalosporin C, 7-aminocephalosporanic acid, and7-(thiophene-2-acetamido)cephalosporanic acid (Abbott, B. and Fukuda,D., Appl. Microbiol. 30(3):413-419 (1975)). CAHs belong to a largerfamily of structurally related enzymes referred to as the carbohydrateesterase family seven (CE-7; see Coutinho, P. M., Henrissat, B.“Carbohydrate-active enzymes: an integrated database approach” in RecentAdvances in Carbohydrate Bioengineering, H. J. Gilbert, G. Davies, B.Henrissat and B. Svensson eds., (1999) The Royal Society of Chemistry,Cambridge, pp. 3-12.)

The CE-7 family includes both CAHs and acetyl xylan esterases (AXEs;E.C. 3.1.1.72). CE-7 family members share a common structural motif andare quite unusual in that they typically exhibit ester hydrolysisactivity for both acetylated xylooligosaccharides and cephalosporin C,suggesting that the CE-7 family represents a single class of proteinswith a multifunctional deacetylase activity against a range of smallsubstrates (Vincent et al., J. Mol. Biol., 330:593-606 (2003)). Vincentet al. describes the structural similarity among the members of thisfamily and defines a signature sequence motif characteristic of the CE-7family.

Members of the CE-7 family are found in plants, fungi {e.g.,Cephalosporidium acremonium), yeasts (e.g., Rhodosporidium toruloides,Rhodotorula glutinis), and bacteria such as Thermoanaerobacterium sp.;Norcardia lactamdurans, and various members of the genus Bacillus(Politino et al, Appl Environ. Microbiol, 63(12):4807-4811 (1997); Sakaiet al, J. Ferment. Bioeng. 85:53-57 (1998); Lorenz, W. and Wiegel, J.,J. Bacteriol 179:5436-5441 (1997); Cardoza et al, Appl. MicrobiolBiotechnol, 54(3):406-412 (2000); Mitsushima et al, supra (1995),Abbott, B. and Fukuda, D., Appl Microbiol. 30(3):413-419 (1975); Vincentet al, supra, Takami et al, NAR, 28(21):4317-4331 (2000); Rey et al,Genome Biol, 5(10): article 77 (2004); Degrassi et al, Microbiology.,146:1585-1591 (2000); U.S. Pat. No. 6,645,233;. U.S. Pat. No. 5,281,525;U.S. Pat. No. 5,338,676; and WO 99/03984. A non-comprehensive list ofCE-7 carbohydrate esterase family members having significant homology toSEQ ID NO: 2 are provided in Table 1.

TABLE 1 Example of CE-7 Enzymes Having Significant Homology to SEQ IDNO: 2. % Amino Source Organism Acid (GENBANK ® Nucleotide Amino AcidIdentity to Accession No. of Sequence Sequence SEQ ID the CE-7 enzyme)(SEQ ID NO:) (SEQ ID NO:) NO: 2. Reference B. subtilis 1 2 100 B.subtilis ATCC ® 31954 ™ SHS 0133 Mitsushima et al. supra (1995) B.subtilis subsp. 3 4 98 Kunst et al., subtilis str. 168 supra.(NP_388200) WO99/03984 B. subtilis BE1010 Payne and Jackson, J.Bacteriol. 173: 2278-2282 (1991)) B. subtilis 5 6 96 U.S. Pat. No.6,465,233 ATCC ® 6633 ™ (YP_077621.1) B. subtilis 29 30 96 Abbott andATCC ® 29233 ™ Fukuda, supra B. licheniformis 7 8 77 Rey et al., supraATCC ® 14580 ™ (YP_077621.1) B. pumilus PS213 9 10 76 Degrassi et al.,(CAB76451.2) supra Clostridium 11 12 57 Copeland et al. thermocellum USDept. of ATCC ® 27405 ™ Energy Joint (ZP_00504991) Genome Institute(JGI-PGF) Direct Submission GENBANK ® ZP_00504991 Thermotoga 13 14 42See neapolitana GENBANK ® (AAB70869.1) AAB70869.1 Thermotoga 15 16 42Nelson et al., maritima MSB8 Nature 399 (NP_227893.1) (6734): 323-329(1999) Bacillus sp. 19 20 40 Siefert et al. NRRL B-14911 J. Craig Venter(ZP_01168674) Institute. Direct Submission Under GENBANK ® ZP_01168674Thermoanaerobacterium 17 18 37 Lorenz and sp. Wiegel, supra (AAB68821.1)Bacillus halodurans 21 22 36 Takami et al., C-125 supra (NP_244192)Thermoanearobacterium — 54 35 Lee, Y. E. saccharolyticum and Zeikus, J.G., (S41858) J Gen Microbiol. (1993), 139 Pt 6: 1235-1243 Bacillusclausii 23 24 33 Kobayashi et al., KSM-K16 Appl. Microbiol. (YP_175265)Biotechnol. 43 (3), 473-481 (1995) Thermotoga 55 57 37 Copeland et al.lettingae US Dept. of (CP000812) Energy Joint Genome Institute DirectSubmission GENBANK ® CP000812 Thermotoga 57 58 41 Copeland et al.Petrophila US Dept. of (CP000702) Energy Joint Genome Institute DirectSubmission GENBANK ® CP000702 Thermotoga sp. 59 60 42 Copeland et al.RQ2 US Dept. of RQ2(a) Energy Joint (CP000969) Genome Institute DirectSubmission GENBANK ® CP000969 Thermotoga sp. 61 63 42 Copeland et al.RQ2 US Dept. of RQ2(b) Energy Joint (CP000969) Genome Institute DirectSubmission GENBANK ® CP000969

The present perhydrolases are all members of the CE-7 carbohydrateesterase family. As described by Vincent et al. (supra), members of thefamily share a common signature motif that is characteristic of thisfamily. A CLUSTALW alignment of the present perhydrolases indicates thatall of the members belong to the CE-7 carbohydrate esterase family. Acomparison of the overall percent amino acid identity amount the presentperhydrolases is provided in Table 2.

TABLE 2 Percent Amino Acid Identity Between Perhydrolases¹ 1 2 3 4 5 6 78 9 10 11 12 13 14 15 1 100 2 99 100 3 99 99 100 4 96 96 97 100 5 77 7677 76 100 6 76 76 76 76 68 100 7 57 57 57 56 56 56 100 8 42 43 43 43 4342 41 100 9 42 43 42 43 43 42 42 72 100 10 42 43 43 43 44 42 43 71 91100 11 41 43 43 43 45 42 43 71 97 91 100 12 41 42 42 42 43 41 42 71 9891 97 100 13 37 37 37 36 39 38 38 64 65 67 66 65 100 14 34 36 35 36 3536 33 36 32 34 34 33 36 100 15 33 34 33 33 32 34 32 30 30 32 31 31 32 34100 ¹= Percent identity determined using blast2seq algorithm usingBLOSUM62, gap open = 11, gap extension = 1, x_drop = 0, expect = 10, andwordsize = 3. Tatiana A. Tatusova, Thomas L. Madden (1999), “Blast 2sequences - a new tool for comparing protein and nucleotide sequences”,FEMS Microbiol Lett. 174: 247-250 1. B. subtilis ATCC ® 31954 ™ 2. B.subtilis BE1010 3. B. subtilis ATCC ® 29233 ™ 4. B. subtilis ATCC ®6633 ™ 5. B. licheniformis 14580 6. B. pumilus PS213 7. C. thermocellumATCC ® 27405 ™ 8. Thermotoga sp. RQ2 (b) 9. Thermotoga sp. RQ2 (a) 10.T. neapolitana 11. T. maritima 12. T. petrophila 13. T. lettingae 14. T.saccharolyticum 15. B. clausii

Although variation is observed in terms of overall percent amino acididentity (i.e. the Clostridium thermocellum ATCC® 27405™ perhydrolase;SEQ ID NO: 12 shares only 57% amino acid identity with the Bacillussubtilis ATCC® 31954™ perhydrolase; SEQ ID NO: 2, while the Bacillusclausii perhydrolase (SEQ ID NO: 24) shares only 33% identity with SEQID NO: 2), each of the present perhydrolase enzymes share the CE-7signature motif. Accordingly, the perhydrolase catalyst of the presentinvention is an enzyme structurally classified as belonging to the CE-7carbohydrate esterase family. Each of the present perhydrolase enzymescomprises the CE-7 signature (diagnostic) motif.

Vincent et al. (supra) analyzed the structure CE-7 esterases andidentified several highly conserved motifs that are diagnostic for thefamily. These highly conserved motifs include the Arg118-Gly119-Gln120(RGQ), Gly179-Xaa180-Ser181-Gln182-Gly183 (GXSQG), and His298-Glu299(HE). In addition, there is a highly conserved Lys267-Xaa268-Asp269(LXD) motif that may be used to further characterize the signaturemotif. All sequence numbering is relative to the numbering of areference sequence (B. subtilis ATCC® 31954™ perhydrolase; SEQ ID NO:2).

In one embodiment, suitable perhydrolytic enzymes can be identified bythe presence of the CE-7 signature motif (Vincent et al., supra). In apreferred embodiment, perhydrolases comprising the CE-7 signature motifare identified using a CLUSTALW alignment against the Bacillus subtilisATCC® 31954™ perhydrolase (SEQ ID NO: 2; i.e. the reference sequenceused for relative amino acid position numbering). As per the amino acidresidue numbering of SEQ ID NO: 2, the CE-7 signature motif comprises 3conserved motifs defined as:

a) Arg118-GIy119-Gln120;

b) Gly179-Xaa180-Ser181-Gln182-Gly183; and

c) His298-Glu299.

Typically, the Xaa at amino acid residue position 180 is glycine,alanine, proline, tryptophan, or threonine. Two of the three amino acidresidues belonging to the catalytic triad are in bold. In oneembodiment, the Xaa at amino acid residue position 180 is selected fromthe group consisting of glycine, alanine, proline, tryptophan, andthreonine.

Further analysis of the conserved motifs within the CE-7 carbohydrateesterase family indicates the presence of an additional conserved motif(LXD at amino acid positions 267-269 of SEQ ID NO: 2) that may be tofurther define a perhydrolase belonging to the CE-7 carbohydrateesterase family (FIGS. 1a-c). In a further embodiment, the signaturemotif defined above includes a forth conserved motif defined as:

Leu267-Xaa268-Asp269.

The Xaa at amino acid residue position 268 is typically isoleucine,valine, or methionine. The forth motif includes the aspartic acidresidue (bold) that is the third member of the catalytic triad(Ser181-Asp269-His298).

Any number of well-known global alignment algorithms (i.e. sequenceanalysis software) may be used to align two or more amino acid sequences(representing enzymes having perhydrolase activity) to determine theexistence of the present signature motif (for example, CLUSTALW orNeedleman and Wunsch (J. Mol. Biol., 48:443-453 (1970)). The alignedsequence(s) is compared to the reference sequence (SEQ ID NO: 2). In oneembodiment, a CLUSTAL alignment (CLUSTALW) using a reference amino acidsequence (as used herein the CAH sequence (SEQ ID NO: 2) from theBacillus subtilis ATCC® 31954™) is used to identify perhydrolasesbelonging to the CE-7 esterase family. The relative numbering of theconserved amino acid residues is based on the residue numbering of thereference amino acid sequence to account for small insertions ordeletions (5 amino acids or less) within the aligned sequence.

A comparison of the overall percent identity among perhydrolasesexemplified herein indicates that enzymes having as little as 33%identity to SEQ ID NO: 2 (while retaining the signature motif) exhibitsignificant perhydrolase activity and are structurally classified asCE-7 carbohydrate esterases. In one embodiment, the presentperhydrolases include enzymes comprising the present signature motif andat least 30%, preferably at least 33%, more preferably at least 40%,even more preferably at least 42%, even more preferably at least 50%,even more preferably at least 60%, even more preferably at least 70%,even more preferably at least 80%, even more preferably at least 90%,and most preferably at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% amino acid identity to SEQ ID NO: 2.

All of the present perhydrolases are comprised of the above signaturemotif as shown in Table 3.

TABLE 3 Conserved motifs found within the present enzymes havingperhydrolase activity. GXSQG LXD motif^(b) HE motif^(a) Perhydrolase RGQmotif^(a) motif^(a) Residue (Residue Sequence (Residue #s) (Residue #s)#s) #s) SEQ ID NO: 2 118-120 179-183 267-269 298-299 SEQ ID NO: 4118-120 179-183 267-269 298-299 SEQ ID NO: 6 118-120 179-183 267-269298-299 SEQ ID NO: 8 119-121 180-184 268-270 299-300 SEQ ID NO: 10118-120 179-183 267-269 298-299 SEQ ID NO: 12 119-121 181-185 269-271300-301 SEQ ID NO: 14 118-120 186-190 272-274 303-304 SEQ ID NO: 16118-120 186-190 272-274 303-304 SEQ ID NO: 18 117-119 180-184 270-272301-302 SEQ ID NO: 20 133-135 193-197 282-284 313-314 SEQ ID NO: 22118-120 181-185 171-173 302-303 SEQ ID NO: 24 117-119 180-184 270-272301-302 SEQ ID NO: 30 118-120 179-183 267-269 298-299 SEQ ID NO: 54117-119 180-184 270-272 301-302 SEQ ID NO: 56 118-120 186-190 272-274303-304 SEQ ID NO: 58 118-120 186-190 272-274 303-304 SEQ ID NO. 60118-120 186-190 272-274 303-304 SEQ ID NO. 62 119-121 187-191 273-275304-305 ^(a)= Conserved motifs defined by Vincent et al., supra used todefine the signature motif. ^(b)= an additional motif identified hereinuseful in further defining the signature motif defined by Vincent etal., supra.

Alternatively, a contiguous signature motif (SEQ ID NO: 53) comprisingthe 4 conserved motifs (RGQ, GXSQG, LXD, and HE; Amino acids residues118-299 of SEQ ID NO: 2) may also be used as a contiguous signaturemotif to identify CE-7 carbohydrate esterases. As such, suitable enzymesexpected to have perhydrolase activity may also be identified as havingat least 30% amino acid identify, preferably at least 36%, morepreferably at least 40%, even more preferably at least 50%, yet morepreferably at least 60%, yet even more preferably at least 70%, yet evenmore preferably at least 80%, yet even more preferably at least 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% amino acid identity toSEQ ID NO: 53 (the 4 conserved motifs found in CE-7 carbohydrateesterases are underlined).

(SEQ ID NO: 53) RGQQSSEDTSISLHGHALGWMTKGILDKDTYYYRGVYLDAVRALEVISSFDEVDETRIGVTGGSQGGGLTIAAAALSDIPKAAVADYPYLSNFERAIDVALEQPYLEINSFFRRNGSPETEVQAMKTLSYFDIMNLADRVKVPVLMSIGLIDKVTPPSTVFAAYNHLETEKELKVYRYFGHE.

A comparison using the contiguous signature sequence against the presentCE-7 esterases having perhydrolase activity is provided in Table 4.BLASTP using default parameters was used.

TABLE 4 Percent Amino Acid Identity of Various CE-7 CarbohydrateEsterases having Perhydrolysis Activity Versus the Contiguous SignatureSequence (SEQ ID NO: 53). Perhydrolase % Identity using E-score SequenceBLASTP (expected) SEQ ID NO: 2 100 3e−92 SEQ ID NO: 4 98 6e−91 SEQ IDNO: 6 98 4e−98 SEQ ID NO: 8 78 1e−78 SEQ ID NO: 10 80 3e−76 SEQ ID NO:12 63 2e−56 SEQ ID NO: 14 51 1e−41 SEQ ID NO: 16 50 6e−35 SEQ ID NO: 2436 7e−21 SEQ ID NO: 30 99 2e−90 SEQ ID NO: 54 40 2e−26 SEQ ID NO: 56 403e−30 SEQ ID NO: 58 46 6e−35 SEQ ID NO. 61 46 6e−35 SEQ ID NO. 62 489e−36

Alternatively, the percent amino acid identity to the complete length ofone or more of the present perhydrolases may also be used. Accordingly,suitable enzymes having an amino acid sequence having at least 30%,preferably at least 33%, preferably at least 40%, preferably at least40%, more preferably at least 50%, more preferably at least 60%, morepreferably at least 70%, even more preferably at least 80%, yet evenmore preferably at least 90%, and most preferably at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% amino acid identity to SEQ IDNO: 2. In a further embodiment, suitable perhydrolase catalysts comprisean amino acid sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10, SEQ ID NO:12, SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 20, SEQ IDNO: 22, SEQ ID NO: 24, SEQ ID NO: 30, SEQ ID NO: 54, SEQ ID NO: 56, SEQID NO: 58, SEQ ID NO: 60, SEQ ID NO: 62. In preferred embodiments,suitable enzymes having perhydrolase activity having at least 90%, atleast 91%, at least 92%, at least 93%, at least 94%, at least 95%, atleast 96%, at least 97%, at least 98%, or at least 99% amino acididentity to SEQ ID NO: 2 or to SEQ ID NO: 10 or to SEQ ID NO: 14 or toSEQ ID NO: 16 may be used.

Suitable perhydrolase enzymes may also include enzymes having one ormore deletions, substitutions, and/or insertions to one of the presentperhydrolase enzymes (e.g. SEQ ID NOs. 2, 10, 14, and 16). As shown inTable 2, CE-7 carbohydrates esterases having perhydrolase activity shareas little as 32% overall amino acid identity. Based on the data providedin the present examples, additional enzymes having perhydrolase activitybelonging to the CE-7 carbohydrate esterase family may have even lowerpercent identity, so long as the enzyme retains the conserved signaturemotif. As such, the numbers of deletions, substitutions, and/orinsertions may vary so long as the conserved signature motifs (see Table3) are found in their relative positions within the enzyme.

An enzyme catalyst comprising a variant enzyme having an amino acidsequence derived from one or more of the present sequences providedherein may also be used in the present processes. U.S. ProvisionalPatent Application No. 61/102520 to DiCosimo et al. (incorporated hereinby reference) describes enzyme catalysts having improved perhydrolysisactivity. More specifically, DiCosimo et al. teaches how certain aminoacid substitutions (alanine, valine, serine or threonine) to a keycysteine residue found within several Thermotoga acetyl xylan esterasesincreases perhydrolysis activity of the variant enzyme when compared tothe wild-type acetyl xylan esterase. Because of the high homologybetween acetyl xylan esterases across the Thermotoga genus, it isexpected that a substitution to the cysteine residue with an alanine,valine, serine, or threonine in any Thermotoga genus will producesimilar results.

In one embodiment, the present processes may use variantThermotoga-derived enzymes having at least 95% sequence identity (or, invarious embodiments, 96%, 97%, 98%, or 99% sequence identity), based onthe CLUSTAL method (such as CLUSTALW) of alignment with pairwisealignment default parameters of KTUPLE=1, GAP PENALTY=3, WINDOW=5 andDIAGONALS SAVED=5, when compared to SEQ ID NOs: 69, 70, 71, 72, or 73,provided that a substitution to amino acid 277 of SEQ ID NOs: 69, 70,71, 72, or 73 is selected from the group consisting of serine,threonine, valine, and alanine.

In a more specific embodiment, the present processes may use a variantThermotoga enzyme comprising an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 69, 70, 71, 72, and 73 provided theamino acid residue 277 is selected from the group consisting of serine,threonine, valine, and alanine.

In a further specific embodiment, the present processes may use avariant Thermotoga neapolitana enzyme comprising an amino acid sequenceSEQ ID NO: 69 wherein amino acid residue 277 is substituted with anamino acid selected from the group consisting of serine, threonine,valine, and alanine.

In a further specific embodiment, the present processes may use avariant Thermotoga maritima enzyme comprising an amino acid sequence SEQID NO: 70 wherein amino acid residue 277 is substituted with an aminoacid selected from the group consisting of serine, threonine, valine,and alanine.

Additionally, it is well within one of skill in the art to identitysuitable enzymes according to the structural similarity found within thecorresponding nucleic acid sequence. Hybridization techniques can beused to identity similar gene sequences. Accordingly, suitableperhydrolase catalysts useful in the present processes comprise an aminoacid sequence encoded by a nucleic acid molecule that hybridizes understringent conditions to a nucleic acid molecule having a nucleic acidsequence selected from the group consisting of SEQ ID NO: 1; SEQ ID NO:3; SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO:13, SEQ ID NO: 15, SEQ ID NO: 17, SEQ ID NO: 19, SEQ ID NO: 21, SEQ IDNO: 23, SEQ ID NO: 29, SEQ ID NO: 55, SEQ ID NO: 57, SEQ ID NO: 59, andSEQ ID NO: 61.

In another embodiment, the perhydrolase catalyst comprises an enzymehaving an amino acid sequence encoded by a nucleic acid molecule thathybridizes under stringent conditions to a nucleic acid sequenceselected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 9, SEQ IDNO: 13, and SEQ ID NO: 15.

The present method produces industrially useful, efficaciousconcentrations of peracids in situ under aqueous reaction conditionsusing the perhydrolase activity of an enzyme belonging to the CE-7family of carbohydrate esterases. In one embodiment, the enzyme havingperhydrolase activity is also classified structurally and functionallyas a cephalosporin C deacetylase (CAH). In another embodiment, theenzyme having perhydrolase activity is classified structurally andfunctionally as an acetyl xylan esterase (AXE).

The peracids produced are quite reactive and may decrease inconcentration over extended periods of time, depending on variables thatinclude, but are not limited to, temperature and pH. As such, it may bedesirable to keep the various reaction components separated, especiallyfor liquid formulations. In one aspect, the hydrogen peroxide source isseparate from either the substrate or the perhydrolase catalyst,preferably from both. This can be accomplished using a variety oftechniques including, but not limited to, the use of multicompartmentchambered dispensers (U.S. Pat. No. 4,585,150) and at the time of usephysically combining the perhydrolase catalyst with an inorganicperoxide and the present substrates to initiate the aqueous enzymaticperhydrolysis reaction. The perhydrolase catalyst may optionally beimmobilized within the body of reaction chamber or separated (e.g.,filtered, etc.) from the reaction product comprising the peracid priorto contacting the surface and/or object targeted for treatment. Theperhydrolase catalyst may be in a liquid matrix or in a solid form(i.e., powdered, tablet) or embedded within a solid matrix that issubsequently mixed with the substrates to initiate the enzymaticperhydrolysis reaction. In a further aspect, the perhydrolase catalystmay be contained within a dissolvable or porous pouch that may be addedto the aqueous substrate matrix to initiate enzymatic perhydrolysis. Inan additional further aspect, a powder comprising the enzyme catalyst issuspended in the substrate (e.g., triacetin), and at time of use ismixed with a source of peroxygen in water.

HPLC Assay Method for Determining the Concentration of Peracid andHydrogen Peroxide.

A variety of analytical methods can be used in the present method toanalyze the reactants and products including, but not limited to,titration, high performance liquid chromatography (HPLC), gaschromatography (GC), mass spectroscopy (MS), capillary electrophoresis(CE), the analytical procedure described by U. Karst et al, (Anal Chem.,69(17):3623-3627 (1997)), and the 2,2′-azino-bis(3-ethylbenzofhazoline)-6-sulfonate (ABTS) assay (S. Minning, et al.,Analytica ChimicaActa 378:293-298 (1999) and WO 2004/058961 A1) asdescribed in the present examples.

Determination of Minimum Biocidal Concentration of Peracids

The method described by J. Gabrielson, et al. (J. Microbiol. Methods50:63-73 (2002)) can be employed for determination of the MinimumBiocidal Concentration (MBC) of peracids, or of hydrogen peroxide andenzyme substrates. The assay method is based on XTT reductioninhibition, where XTT((2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-5-[(phenylamino)carbonyl]-2H-tetrazolium,inner salt, monosodium salt) is a redox dye that indicates microbialrespiratory activity by a change in optical density (OD) measured at 490nm or 450 nm. However, there are a variety of other methods availablefor testing the activity of disinfectants and antiseptics including, butnot limited to, viable plate counts, direct microscopic counts, dryweight, turbidity measurements, absorbance, and bioluminescence (see,for example Brock, Semour S., Disinfection, Sterilization, andPreservation, 5^(th) edition, Lippincott Williams & Wilkins,Philadelphia, Pa., USA; 2001).

Uses of Enzymatically Prepared Peracid Compositions

The enzyme catalyst-generated peracid produced according to the presentmethods can be used in a variety of hard surface/inanimate objectapplications for reduction of concentrations of microbial, fungal,prion-related, and viral contamination, such as decontamination ofmedical instruments (e.g., endoscopes), textiles (e.g., garments,carpets), food preparation surfaces, food storage and food-packagingequipment, materials used for the packaging of food products, chickenhatcheries and grow-out facilities, animal enclosures, and spent processwaters that have microbial and/or virucidal activity. Theenzyme-generated peracids may be used in formulations designed toinactivate prions (e.g. certain proteases) to additionally providebiocidal activity. In a preferred aspect, the present peracidcompositions are particularly useful as a disinfecting agent fornon-autoclavable medical instruments and food packaging equipment. Asthe peracid-containing formulation may be prepared using GRAS orfood-grade components (enzyme, enzyme substrate, hydrogen peroxide, andbuffer), the enzyme-generated peracid may also be used fordecontamination of animal carcasses, meat, fruits and vegetables, or fordecontamination of prepared foods. The enzyme-generated peracid may beincorporated into a product whose final form is a powder, liquid, gel,film, solid or aerosol. The enzyme-generated peracid may be diluted to aconcentration that still provides an efficacious decontamination.

The compositions comprising an efficacious concentration of peracid canbe used to disinfect surfaces and/or objects contaminated (or suspectedof being contaminated) with viable pathogenic microbial contaminants bycontacting the surface or object with the products produced by thepresent processes. As used hereins “contacting” refers to placing adisinfecting composition comprising an effective concentration ofperacid in contact with the surface or inanimate object suspected ofcontamination with a disease-causing entity for a period of timesufficient to clean and disinfect. Contacting includes spraying,treating, immersing, flushing, pouring on or in, mixing, combining,painting, coating, applying, affixing to and otherwise communicating aperacid solution or composition comprising an efficacious concentrationof peracid, or a solution or composition that forms an efficaciousconcentration of peracid, with the surface or inanimate object suspectedof being contaminated with a concentration of a microbial population.The disinfectant compositions may be combined with a cleaningcomposition to provide both cleaning and disinfection. Alternatively, acleaning agent (e.g., a surfactant or detergent) may be incorporatedinto the formulation to provide both cleaning and disinfection in asingle composition.

The compositions comprising an efficacious concentration of peracid canalso contain at least one additional antimicrobial agent, combinationsof prion-degrading proteases, a virucide, a sporicide, or a biocide.Combinations of these agents with the peracid produced by the claimedprocesses can provide for increased and/or synergistic effects when usedto clean and disinfect surfaces and/or objects contaminated (orsuspected of being contaminated) with pathogenic microorganisms, spores,viruses, fungi, and/or prions. Suitable antimicrobial agents includecarboxylic esters (e.g., p-hydroxy alkyl benzoates and alkylcinnamates), sulfonic acids (e.g., dodecylbenzene sulfonic acid),iodo-compounds or active halogen compounds (e.g., elemental halogens,halogen oxides (e.g., NaOCl, HOCl, HOBr, ClO₂), iodine, interhalides(e.g., iodine monochloride, iodine dichloride, iodine trichloride,iodine tetrachloride, bromine chloride, iodine monobromide, or iodinedibromide), polyhalides, hypochlorite salts, hypochlorous acid,hypobromite salts, hypobromous acid, chloro- and bromo-hydantoins,chlorine dioxide, and sodium chlorite), organic peroxides includingbenzoyl peroxide, alkyl benzoyl peroxides, ozone, singlet oxygengenerators, and mixtures thereof, phenolic derivatives (e.g., o-phenylphenol, o-benzyl-p-chlorophenol, tert-amyl phenol and C₁-C₆ alkylhydroxy benzoates), quaternary ammonium compounds (e.g.,alkyldimethylbenzyl ammonium chloride, dialkyldimethyl ammonium chlorideand mixtures thereof), and mixtures of such antimicrobial agents, in anamount sufficient to provide the desired degree of microbial protection.Effective amounts of antimicrobial agents include about 0.001 wt % toabout 60 wt % antimicrobial agent, about 0.01wt % to about 15 wt %antimicrobial agent, or about 0.08 wt % to about 2.5 wt % antimicrobialagent.

In one aspect, the peracids formed by the present process can be used toreduce the concentration of viable microbial contaminants (e.g. a viablemicrobial population) when applied on and/or at a locus. As used herein,a “locus” comprises part or all of a target surface suitable fordisinfecting or bleaching. Target surfaces include all surfaces that canpotentially be contaminated with microorganisms, viruses, spores, fungi,prions or combinations thereof. Non-limiting examples include equipmentsurfaces found in the food or beverage industry (such as tanks,conveyors, floors, drains, coolers, freezers, equipment surfaces, walls,valves, belts, pipes, drains, joints, crevasses, combinations thereof,and the like); building surfaces (such as walls, floors and windows);non-food-industry related pipes and drains, including water treatmentfacilities, pools and spas, and fermentation tanks; hospital orveterinary surfaces (such as walls, floors, beds, equipment, (such asendoscopes) clothing worn in hospital/veterinary or other healthcaresettings, including clothing, scrubs, shoes, and other hospital orveterinary surfaces); restaurant surfaces; bathroom surfaces; toilets;clothes and shoes; surfaces of barns or stables for livestock, such aspoultry, cattle, dairy cows, goats, horses and pigs; hatcheries forpoultry or for shrimp; and pharmaceutical or biopharmaceutical surfaces(e.g., pharmaceutical or biopharmaceutical manufacturing equipment,pharmaceutical or biopharmaceutical ingredients, pharmaceutical orbiopharmaceutical excipients). Additional hard surfaces also includefood products, such as beef, poultry, pork, vegetables, fruits, seafood,combinations thereof, and the like. The locus can also include waterabsorbent materials such as infected linens or other textiles. The locusalso includes harvested plants or plant products including seeds, corns,tubers, fruit, and vegetables, growing plants, and especially cropgrowing plants, including cereals, leaf vegetables and salad crops, rootvegetables, legumes, berried fruits, citrus fruits and hard fruits.

Non-limiting examples of hard surface materials are metals (e.g., steel,stainless steel, chrome, titanium, iron, copper, brass, aluminum, andalloys thereof), minerals (e.g., concrete), polymers and plastics (e.g.,polyolefins, such as polyethylene, polypropylene, polystyrene,poly(meth)acrylate, polyacrylonitrile, polybutadiene,poly(acrylonitrile, butadiene, styrene), poly(acrylonitrile, butadiene),acrylonitrile butadiene; polyesters such as polyethylene terephthalate;and polyamides such as nylon). Additional surfaces include brick, tile,ceramic, porcelain, wood, vinyl, linoleum, and carpet.

Peracids have also been reported to be useful in preparing bleachingcompositions for laundry detergent applications (U.S. Pat. No.3,974,082; U.S. Pat. No. 5,296,161; and U.S. Pat. No. 5,364,554). Somebleaching applications may require a controlled level of bleachingactivity for optimal performance. In an additional aspect, the peracidsformed by the present process can be used for bleaching of laundry ortextiles, where similar limitations to the concentration of peracidgenerated for bleaching are also desirable.

Recombinant Microbial Expression

The genes and gene products of the instant sequences may be produced inheterologous host cells, particularly in the cells of microbial hosts.Preferred heterologous host cells for expression of the instant genesand nucleic acid molecules are microbial hosts that can be found withinthe fungal or bacterial families and which grow over a wide range oftemperature, pH values, and solvent tolerances. For example, it iscontemplated that any of bacteria, yeast, and filamentous fungi maysuitably host the expression of the present nucleic acid molecules. Theperhydrolase may be expressed intracellularly, extracellularly, or acombination of both intracellularly and extracellularly, whereextracellular expression renders recovery of the desired protein from afermentation product more facile than methods for recovery of proteinproduced by intracellular expression. Transcription, translation and theprotein biosynthetic apparatus remain invariant relative to the cellularfeedstock used to generate cellular biomass; functional genes will beexpressed regardless. Examples of host strains include, but are notlimited to bacterial, fungal or yeast species such as Aspergillus,Trichoderma, Saccharomyces, Pichia, Phaffia, Candida, Hansenula,Yarrowia, Salmonella, Bacillus, Acinetobacter, Zymomonas, Agrobacterium,Erythrobacter, Chlorobium, Chromatium, Flavobacterium, Cytophaga,Rhodobacter, Rhodococcus, Streptomyces, Brevibacterium, Corynebacteria,Mycobacterium, Deinococcus, Escherichia, Erwinia, Pantoea, Pseudomonas,Sphingomonas, Methylomonas, Meihylobacter, Methylococcus, Melhylosinus,Methylomicrobium, Methylocystis, Alcaligenes, Synechocystis,Synechococcus, Anabaena, Thiobacillus, Methanobacterium, Klebsiella, andMyxococcus. In one embodiment, bacterial host strains includeEscherichia, Bacillus, and Pseudomonas. In a preferred embodiment, thebacterial host cell is Escherichia coli.

Large-scale microbial growth and functional gene expression may use awide range of simple or complex carbohydrates, organic acids andalcohols or saturated hydrocarbons, such as methane or carbon dioxide inthe case of photosynthetic or chemoautotrophic hosts, the form andamount of nitrogen, phosphorous, sulfur, oxygen, carbon or any tracemicronutrient including small inorganic ions. The regulation of growthrate may be affected by the addition, or not, of specific regulatorymolecules to the culture and which are not typically considered nutrientor energy sources.

Vectors or cassettes useful for the transformation of suitable hostcells are well known in the art. Typically the vector or cassettecontains sequences directing transcription and translation of therelevant gene, a selectable marker, and sequences allowing autonomousreplication or chromosomal integration. Suitable vectors comprise aregion 5′ of the gene which harbors transcriptional initiation controlsand a region 3′ of the DNA fragment which controls transcriptionaltermination. It is most preferred when both control regions are derivedfrom genes homologous to the transformed host cell and/or native to theproduction host, although such control regions need not be so derived.

Initiation control regions or promoters, which are useful to driveexpression of the present cephalosporin C deacetylase coding region inthe desired host cell are numerous and familiar to those skilled in theart. Virtually any promoter capable of driving these genes is suitablefor the present invention including but not limited to CYC1, BIS3, GAL1,GAL10, ADH1, PGK, PHO5, GAPDH, ADC1, TRP1, URA3, LEU2, ENO, TPI (usefulfor expression in Saccharomyces); AOX1 (useful for expression inPichia); and lac, ara, tet, trp, IP_(L), IP_(R), T7, tac, and trc(useful for expression in Escherichia coli) as well as the amy, apr, nprpromoters and various phage promoters useful for expression in Bacillus.

Termination control regions may also be derived from various genesnative to the preferred host cell. In one embodiment, the inclusion of atermination control region is optional. In another embodiment, thechimeric gene includes a termination control region derived thepreferred host cell.

Industrial Production

A variety of culture methodologies may be applied to produce the presentperhydrolase catalysts. For example, large-scale production of aspecific gene product overexpressed from a recombinant microbial hostmay be produced by both batch and continuous culture methodologies.

A classical batch culturing method is a closed system where thecomposition of the media is set at the beginning of the culture and notsubject to artificial alterations during the culturing process. Thus, atthe beginning of the culturing process, the media is inoculated with thedesired organism or organisms and growth or metabolic activity may occurwithout adding anything further to the system. Typically, however, a“batch” culture is batch with respect to the addition of carbon sourceand attempts are often made to control factors such as pH and oxygenconcentration. In batch systems the metabolite and biomass compositionsof the system change constantly up to the time the culture isterminated. Within batch cultures cells moderate through a static lagphase to a high growth log phase and finally to a stationary phase wheregrowth rate is diminished or halted. If untreated, cells in thestationary phase will eventually die. Cells in log phase are oftenresponsible for the bulk of production of end product or intermediate insome systems. Stationary or post-exponential phase production can beobtained in other systems.

A variation on the standard batch system is the fed-batch system.Fed-batch culture processes are also suitable in the present inventionand comprise a typical batch system except that the substrate is addedin increments as the culture progresses. Fed-batch systems are usefulwhen catabolite repression is apt to inhibit the metabolism of the cellsand where it is desirable to have limited amounts of substrate in themedia. Measurement of the actual substrate concentration in fed-batchsystems is difficult and is estimated on the basis of the changes ofmeasurable factors such as pH, dissolved oxygen and the partial pressureof waste gases such as CO₂. Batch and fed-batch culturing methods arecommon and well known in the art and examples may be found in Thomas D.Brock in Biotechnology: A Textbook of Industrial Microbiology, SecondEdition, Sinauer Associates, Inc., Sunderland, Mass. (1989) andDeshpande, Mukund V., Appl. Biochem. Biotechnol., 36:227 (1992).

Commercial production of the desired perhydrolase catalysts may also beaccomplished with a continuous culture. Continuous cultures are an opensystem where a defined culture media is added continuously to abioreactor and an equal amount of conditioned media is removedsimultaneously for processing. Continuous cultures generally maintainthe cells at a constant high liquid phase density where cells areprimarily in log phase growth. Alternatively, continuous culture may bepracticed with immobilized cells where carbon and nutrients arecontinuously added and valuable products, by-products or waste productsare continuously removed from the cell mass. Cell immobilization may beperformed using a wide range of solid supports composed of naturaland/or synthetic materials.

Continuous or semi-continuous culture allows for the modulation of onefactor or any number of factors that affect cell growth or end productconcentration. For example, one method will maintain a limiting nutrientsuch as the carbon source or nitrogen level at a fixed rate and allowall other parameters to moderate. In other systems a number of factorsaffecting growth can be altered continuously while the cellconcentration, measured by media turbidity, is kept constant. Continuoussystems strive to maintain steady state growth conditions and thus thecell loss due to media being drawn off must be balanced against the cellgrowth rate in the culture. Methods of modulating nutrients and growthfactors for continuous culture processes as well as techniques formaximizing the rate of product formation are well known in the art ofindustrial microbiology and a variety of methods are detailed by Brock,supra.

Fermentation media in the present invention must contain suitable carbonsubstrates. Suitable substrates may include but are not limited tomonosaccharides such as glucose and fructose, disaccharides such aslactose or sucrose, polysaccharides such as starch or cellulose ormixtures thereof and unpurified mixtures from renewable feedstocks suchas cheese whey permeate, cornsteep liquor, sugar beet molasses, andbarley malt. Additionally, the carbon substrate may also be one-carbonsubstrates such as carbon dioxide, methane or methanol (for example,when the host cell is a methylotrophic microorganism). Similarly,various species of Candida will metabolize alanine or oleic acid (Suiteret al., Arch. Microbiol, 153:485-489 (1990)). Hence, it is contemplatedthat the source of carbon utilized in the present invention mayencompass a wide variety of carbon-containing substrates and will onlybe limited by the choice of organism.

Recovery of the desired perhydrolase catalysts from a batch or fed batchfermentation, or continuous culture, may be accomplished by any of themethods that are known to those skilled in the art. For example, whenthe perhydrolase catalyst is produced intracellularly, the cell paste isseparated from the culture medium by centrifugation or membranefiltration, optionally washed with water or an aqueous buffer at adesired pH, then a suspension of the cell paste in an aqueous buffer ata desired pH is homogenized to produce a cell extract containing thedesired perhydrolase catalyst. The cell extract may optionally befiltered through an appropriate filter aid such as celite or silica toremove cell debris prior to a heat-treatment step to precipitateundesired protein from the perhydrolase catalyst solution. The solutioncontaining the desired perhydrolase catalyst may then be separated fromthe precipitated cell debris and protein by membrane filtration orcentrifugation, and the resulting partially-purified perhydrolasecatalyst solution concentrated by additional membrane filtration, thenoptionally mixed with an appropriate carrier (for example, maltodextrin,phosphate buffer, citrate buffer, or mixtures thereof) and spray-driedto produce a solid powder comprising the desired perhydrolase catalyst.

Applicants specifically incorporate the entire contents of all citedreferences in this disclosure. Further, when an amount, concentration,or other value or parameter is given either as a range, preferred range,or a list of upper preferable values and lower preferable values, thisis to be understood as specifically disclosing all ranges formed fromany pair of any upper range limit or preferred value and any lower rangelimit or preferred value, regardless of whether ranges are separatelydisclosed. Where a range of numerical values is recited herein, unlessotherwise stated, the range is intended to include the endpointsthereof, and all integers and fractions within the range. It is notintended that the scope be limited to the specific values recited whendefining a range.

General Methods

The following examples are provided to demonstrate preferred aspects ofthe invention. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples which follow representtechniques discovered by the inventor to function well in the practiceof the invention, and thus can be considered to constitute preferredmodes for its practice. However, those of skill in the art should, inlight of the present disclosure, appreciate that many changes can bemade in the specific embodiments which are disclosed and still obtain alike or similar result without departing from the spirit and scope ofthe invention.

All reagents and materials were obtained from DIFCO Laboratories(Detroit, Mich.), GIBCO/BRL (Gaithersburg, Md.), TCI America (Portland,Oreg.), Roche Diagnostics Corporation (Indianapolis, Ind.) orSigma/Aldrich Chemical Company (St. Louis, Mo.), unless otherwisespecified.

The following abbreviations in the specification correspond to units ofmeasure, techniques, properties, or compounds as follows: “sec” or “s”means second(s), “min” means minute(s), “h” or “hr” means hour(s), “μL”means microliter(s), “mL” means milliliter(s), “L” means liter(s), “mM”means millimolar, “M” means molar, “mmol” means millimole(s), “ppm”means part(s) per million, “wt” means weight, “wt %” means weightpercent, “g” means gram(s), “μg” means microgram(s), “ng” meansnanogram(s), “g” means gravity, “HPLC” means high performance liquidchromatography, “dd H₂O” means distilled and deionized water, “dew”means dry cell weight, “ATCC” or “ATCC®” means the American Type CultureCollection (Manassas, Va.), “U” means unit(s) of perhydrolase activity,“rpm” means revolution(s) per minute, and “EDTA” meansethylenediaminetetraacetic acid.

EXAMPLE 1 Construction of a katG Catalase Disrupted E. coli Strain

The kanamycin resistance gene (kan; SEQ ID NO: 35) was amplified fromthe plasmid pKD13 (SEQ ID NO: 36) by PCR (0.5 min at 94° C., 0.5 min at55° C., 1 min at 70° C., 30 cycles) using primers identified as SEQ IDNO: 37 and SEQ ID NO: 38 to generate the PCR product identified as SEQID NO: 39. The katG nucleic acid sequence is provided as SEQ ID NO: 40and the corresponding amino acid sequence is SEQ ID NO: 41, E. coli MG1655 (ATCC® 47076™) was transformed with the temperature-sensitiveplasmid pKD46 (SEQ ID NO: 42), which contains the λ-Red recombinasegenes (Datsenko and Wanner, 2000, PNAS USA 97:6640-6645), and selectedon LB-amp plates for 24 h at 30° C. MG1655/pKD46 was transformed with50-500 ng of the PCR product by electroporation (BioRad Gene Pulser, 0.2cm cuvette, 2.5 kV, 200 W, 25 uF), and selected on LB-kan plates for 24h at 37° C. Several colonies were streaked onto LB-kan plates andincubated overnight at 42° C. to cure the pKD46 plasmid. Colonies werechecked to confirm a phenotype of kanR/ampS. Genomic DNA was isolatedfrom several colonies using the PUREGENE® DNA purification system, andchecked by PCR to confirm disruption of the katG gene using primersidentified as SEQ ID NO: 43 and SEQ ID NO: 44. Several katG-disruptedstrains were transformed with the temperature-sensitive plasmid pCP20(SEQ ID NO: 45), which contains the FLP recombinase, used to excise thekan gene, and selected on LB-amp plates for 24 h at 37° C. Severalcolonies were streaked onto LB plates and incubated overnight at 42° C.to cure the pCP20 plasmid. Two colonies were checked to confirm aphenotype of kanS/ampS, and called MG1655 KatG1 and MG1655 KatG2.

EXAMPLE 2 Construction of a katE Catalase Disrupted E. coli Strain

The kanamycin resistance gene (SEQ ID NO: 35) was amplified from theplasmid pKD13 (SEQ ID NO: 36) by PCR (0.5 min at 94° C., 0.5 min at 55°C. 1 min at 70° C., 30 cycles) using primers identified as SEQ ID NO: 46and SEQ ID NO: 47 to generate the PCR product identified as SEQ ID NO:48. The katE nucleic acid sequence is provided as SEQ ID NO: 49 and thecorresponding amino acid sequence is SEQ ID NO: 50. E. coli MG1655(ATCC® 47076™) was transformed with the temperature-sensitive plasmidpKD46 (SEQ ID NO: 42), which contains the λ-Red recombinase genes, andselected on LB-amp plates for 24 h at 30° C. MG1655/pKD46 wastransformed with 50-500 ng of the PCR product by electroporation (BioRadGene Pulser, 0.2 cm cuvette, 2.5 kV, 200 W, 25 uF), and selected onLB-kan plates for 24 h at 37° C. Several colonies were streaked ontoLB-kan plates and incubated overnight at 42° C. to cure the pKD46plasmid. Colonies were checked to confirm a phenotype of kanR/ampS.Genomic DNA was isolated from several colonies using the PUREGENE DNApurification system, and checked by PCR to confirm disruption of thekatE gene using primers identified as SEQ ID NO: 51 and SEQ ID NO: 52.Several katE-disrupted strains were transformed with thetemperature-sensitive plasmid pCP20 (SEQ ID NO: 45), which contains theFLP recombinase, used to excise the kan gene, and selected on LB-ampplates for 24 h at 37° C. Several colonies were streaked onto LB platesand incubated overnight at 42° C. to cure the pCP20 plasmid. Twocolonies were checked to confirm a phenotype of kanS/ampS, and calledMG1655 KatE1 and MG1655 KatE2.

EXAMPLE 3 Construction of a katG Catalase and katE Catalase Disrupted E.coli Strain (KLP18)

The kanamycin resistance gene (SEQ ID NO: 35) was amplified from theplasmid pKD13 (SEQ ID NO: 36) by PCR (0.5 min at 94° C., 0.5 min at 55°C., 1 min at 70° C., 30 cycles) using primers identified as SEQ ID NO:46 and SEQ ID NO: 47 to generate the PCR product identified as SEQ IDNO: 48. E. coli MG1655 KatG1 (EXAMPLE 13) was transformed with thetemperature-sensitive plasmid pKD46 (SEQ ID NO: 42), which contains theλ-Red recombinase genes, and selected on LB-amp plates for 24 h at 30°C. MG1655 KatG1/pKD46 was transformed with 50-500 ng of the PCR productby electroporation (BioRad Gene Pulser, 0.2 cm cuvette, 2.5 kV, 200 W,25 uF), and selected on LB-kan plates for 24 h at 37° C. Severalcolonies were streaked onto LB-kan plates and incubated overnight at 42°C. to cure the pKD46 plasmid. Colonies were checked to confirm aphenotype of kanR/ampS. Genomic DNA was isolated from several coloniesusing the PUREGENE® DNA purification system, and checked by PCR toconfirm disruption of the katE gene using primers identified as SEQ IDNO: 51 and SEQ ID NO: 52. Several katE-disrupted strains (Δ katE) weretransformed with the temperature-sensitive plasmid pCP20 (SEQ ID NO:45), which contains the FLP recombinase, used to excise the kan gene,and selected on LB-amp plates for 24 h at 37° C. Several colonies werestreaked onto LB plates and incubated overnight at 42° C. to cure thepCP20 plasmid. Two colonies were checked to confirm a phenotype ofkanS/ampS, and called MG1655 KatG1 KatE18.1 and MG1655 KatG1KatE23.MG1655 KatG1KatE18.1 is designated E. coli KLP18.

EXAMPLE 4 Cloning and Expression of Perhydrolase from Thermotoganeapolitana

The gene encoding acetyl xylan esterase from Thermotoga neapolitana asreported in GENBANK® (accession #U58632) was synthesized using codonsoptimized for expression in E. coli (DNA 2.0, Menlo Park, Calif.). Thegene was subsequently amplified by PCR (0.5 min at 94° C., 0.5 min at55° C., 1 min at 70° C., 30 cycles) using primers identified as SEQ IDNO: 66 and SEQ ID NO: 67. The resulting nucleic acid product (SEQ ID NO:68) was subcloned into pTrcHis2-TOPO® to generate the plasmid identifiedas pSW196. The plasmid pSW196 was used to transform E. coli KLP18 togenerate the strain KLP18/pSW196. KLP18/pSW196 was grown in LB media at37° C. with shaking up to OD600 nm=0.4-0.5, at which time IPTG was addedto a final concentration of 1 mM, and incubation continued for 2-3 h.Cells were harvested by centrifugation and SDS-PAGE was performed toconfirm expression of the perhydrolase at 20-40% of total solubleprotein.

EXAMPLE 5 Cloning and Expression of Perhydrolase from Thermotogamaritima MSB8

The gene encoding acetyl xylan esterase from Thermotoga maritima MSB8 asreported in GENBANK® (accession #NP_(—)227893.1) was synthesized (DNA2.0, Menlo Park, Calif.). The gene was subsequently amplified by PCR(0.5 min @94° C., 0.5 min @55° C., 1 min @70° C., 30 cycles) usingprimers identified as SEQ ID NO: 63 and SEQ ID NO: 64. The resultingnucleic acid product (SEQ ID NO: 65) was cut with restriction enzymesPstI and XbaI and subcloned between the PstI and XbaI sites in pUC19 togenerate the plasmid identified as pSW207. The plasmid pSW207 was usedto transform E. coli KLP18 to generate the strain identified asKLP18/pSW207. KLP18/pSW207 was grown in LB media at 37 C with shaking upto OD600 nm =0.4-0.5, at which time IPTG was added to a finalconcentration of 1 mM, and incubation continued for 2-3 hrs. Cells wereharvested by centrifugation and SDS-PAGE was performed to confirmexpression of the perhydrolase enzyme at 20-40% of total solubleprotein.

EXAMPLE 6 Cloning and Expression of Perhydrolase from Bacillus subtilisATCC® 31954™

Genomic DNA was isolated from Bacillus subtilis ATCC® 31954™ using thePUREGENE® DNA purification system (Gentra Systems, Minneapolis Minn.).The perhydrolase gene was amplified from the genomic DNA by PCR (0.5 minat 94° C., 0.5 min at 55° C., 1 min at 70° C., 30 cycles) using primersidentified as SEQ ID NO: 25 and SEQ ID NO: 26. The resulting nucleicacid product (SEQ ID NO: 27) was cut with restriction enzymes PstI andXbaI and subcloned between the PstI and XbaI sites in pUC19 to generatethe plasmid identified as pSW194. The plasmid pSW194 was used totransform E. coli KLP18 to generate the strain identified asKLP18/pSW194. KLP18/pSW194 was grown in LB media at 37° C. with shakingup to OD600 nm 0.4-0.5, at which time IPTG was added to a finalconcentration of 1 mM, and incubation continued for 2-3 h. Cells wereharvested by centrifugation and SDS-PAGE was performed to confirmexpression of the perhydrolase at 20-40% of total soluble protein.

EXAMPLE 7 Cloning and Expression of Perhydrolase from Bacillus subtilisBE1010

Genomic DNA was isolated from Bacillus subtilis BE1010 (Payne andJackson 1991 J. Bacteriol. 173:2278-2282) using the PUREGENE® DNApurification system (Gentra Systems), The perhydrolase gene wasamplified from the genomic DNA by PCR (0.5 min at 94° C., 0.5 min at 55°C., 1 min at 70° C., 30 cycles) using primers identified as SEQ ID NO:25 and SEQ ID NO: 26. The resulting nucleic acid product (SEQ ID NO: 28)was cut with restriction enzymes PstI and XbaI and subcloned between thePstI and XbaI sites in pUC19 to generate the plasmid identified aspSW189. The plasmid pSW189 was used to transform E. coli KLP18 togenerate the strain identified as KLP18/pSW189. KLP18/pSW189 was grownin LB media at 37° C. with shaking up to OD600 nm=0.4-0.5, at which timeIPTG was added to a final concentration of 1 mM, and incubationcontinued for 2-3 h. Cells were harvested by centrifugation and SDS-PAGEwas performed to confirm expression of the perhydrolase at 20-40% oftotal soluble protein.

EXAMPLE 8 Cloning and Expression of Perhydrolase from Bacillus pumilusPS213

The gene encoding acetyl xylan esterase (axel) from B. pumilus PS213 asreported in GENBANK® (accession #AJ249957) was synthesized using codonsoptimized for expression in E. coli (DNA 2.0, Menlo Park Calif.). Thegene was subsequently amplified by PCR (0.5 min at 94° C., 0.5 min at55° C., 1 min at 70° C., 30 cycles) using primers identified as SEQ IDNO: 33 and SEQ ID NO: 34. The resulting nucleic acid product (SEQ ID NO:53) was subcloned into pTrcHis2-TOPO® (Invitrogen, Carlsbad Calif.) togenerate the plasmid identified as pSW195. The plasmid pSW195 was usedto transform E. coli KLP18 to generate the strain identified asKLP18/pSW195. KLP18/pSW195 was grown in LB media at 37° C. with shakingup to OD600 nm=0.4-0.5, at which time IPTG was added to a finalconcentration of 1 mM, and incubation continued for 2-3 h. Cells wereharvested by centrifugation and SDS-PAGE was performed to confirmexpression of the perhydrolase at 20-40% of total soluble protein.

EXAMPLE 9 Cloning and Expression of Perhydrolase from Bacilluslicheniformis ATCC®14580™

Genomic DNA was isolated from Bacillus licheniformis ATCC® 14580™ usingthe PUREGENE® DNA purification system. The perhydrolase gene wasamplified from the genomic DNA by PCR (0.5 min at 94° C., 0.5 min at 55°C., 1 min at 70° C., 30 cycles) using primers identified as SEQ ID NO:31 and SEQ ID NO: 32. The resulting nucleic acid product (SEQ ID NO: 7)was subcloned into pTrcHis2-TOPO® to generate the plasmid identified aspSW191. The plasmid pSW191 was used to transform E. coli KLP18 togenerate the strain identified as KLP18/pSW191. KLP18/pSW191 was grownin LB media at 37° C. with shaking up to OD600 nm=0.4-0.5, at which timeIPTG was added to a final concentration of 1 mM, and incubationcontinued for 2-3 h. Cells were harvested by centrifugation and SDS-PAGEwas performed to confirm expression of the perhydrolase at 20-40% oftotal soluble protein.

EXAMPLE 10 Fermentation of E. coli KLP18 Transformants ExpressingPerhydrolase

A fermentor seed culture was prepared by charging a 2-L shake flask with0.5 L seed medium containing yeast extract (Amberx 695, 5.0 g/L), K₂HPO₄(10.0 g/L), KH₂PO₄ (7.0 g/L), sodium citrate dihydrate (1.0 g/L),(NH₄)₂SO₄ (4.0 g/L), MgSO₄ heptahydrate (1.0 g/L) and ferric ammoniumcitrate (0.10 g/L). The pH of the medium was adjusted to 6.8 and themedium was sterilized in the flask. Post sterilization additionsincluded glucose (50 wt %, 10.0 mL) and 1mL ampicillin (25 mg/mL) stocksolution. The seed medium was inoculated with a 1-mL culture of E. coliKLP18/pSW189, E. coli KLP18/pSW191, E. coli KLP18/pSW194, E. coliKLP18/pSW195, E. coli KLP18/pSW196, or E. coli KLP18/pSW207 in 20%glycerol, and cultivated at 35° C. and 300 rpm. The seed culture wastransferred at ca. 1-2 OD₅₅₀ to a 14 L fermentor (Braun) with 8 L ofmedium at 35° C. containing KH₂PO₄ (3.50 g/L), FeSO₄ heptahydrate (0.05g/L), MgSO₄ heptahydrate (2.0 g/L), sodium citrate dihydrate (1.90 g/L),yeast extract (Ambrex 695, 5.0 g/L), Biospumex153K antifoam (0.25 mL/L,Cognis Corporation), NaCl (1.0 g/L), CaCl₂ dihydrate (10 g/L), and NITtrace elements solution (10 mL/L). The trace elements solution containedcitric acid monohydrate (10 g/L), MnSO₄ hydrate (2 g/L), NaCl (2 g/L),FeSO₄ heptahydrate (0.5 g/L), ZnSO₄ heptahydrate (0.2 g/L), CuSO₄pentahydrate (0.02 g/L) and NaMoO₄ dihydrate (0.02 g/L). Poststerilization additions included glucose solution (50% w/w, 80.0 g) andampicillin (25 mg/mL) stock solution (16.00 mL). Glucose solution (50%w/w) was used for fed batch. Glucose feed was initiated when glucoseconcentration decreased to 0.5 g/L, starting at 0.31 g feed/min andincreasing progressively each hour to 0.36, 0.42, 0.49, 0.57, 0.66,0.77, 0.90, 1.04, 1.21, 1.41 1.63 g/min respectively; the rate remainedconstant afterwards. Glucose concentration in the medium was monitoredand if the concentration exceeded 0.1 g/L the feed rate was decreased orstopped temporarily. Induction was initiated between OD₅₅₀=56 andOD₅₅₀=80 with addition of 16 mL IPTG (0.5 M) for the various strains.The dissolved oxygen (DO) concentration was controlled at 25% of airsaturation. The DO was controlled first by impeller agitation rate (400to 1400 rpm) and later by aeration rate (2 to 10 slpm). The pH wascontrolled at 6.8. NH₄OH (29% w/w) and H₂SO₄ (2.0% w/v) were used for pHcontrol. The head pressure was 0.5 bars. The cells were harvested bycentrifugation 16 h post IPTG addition.

EXAMPLE 11 Dependence of Specific Activity on pH for CE-7Esterases/Perhydrolases

A cell extract of an E. coli transformant expressing perhydrolase fromThermotoga neapolitana (KLP18/pSW196), Thermotoga maritima MSB8(KLP18/pSW207), Bacillus pumilus PS213 (KLP18/pSW195), Bacillus subtilisBE1010 (KLP18/pSW189), Bacillus subtilis ATCC® 31954™ (KLP18/pSW194), orBacillus licheniformis ATCC® 14580™ (KLP18/pSW191) was prepared bypassing a suspension of cell paste (20 wt % wet cell weight) in 0.05 Mpotassium phosphate buffer (pH 7.0) containing dithiothreitol (1 mM)twice through a French press having a working pressure of 16,000 psi(110 MPa). The crude extract was then centrifuged at 20,000×g to removecellular debris, producing a clarified cell extract that was assayed fortotal soluble protein (Bicinchoninic Acid Kit for Protein Detenuination,Sigma Aldrich catalog #BCA1-KT). A portion of the clarified Thermotogamaritima MSB8 or Thermotoga neapolitana perhydrolase-containing extractwas additionally heated for 20 min at 75° C., followed immediately bycooling in an ice/water bath to 5° C. The resulting mixture wascentrifuged to remove precipitated protein, and the supernatantcollected and assayed for total soluble protein as before. SDS-PAGE ofthe heat-treated supernatant indicated that the perhydrolase constitutedat least ca. 90% of the total soluble protein present in thesupernatant.

Reactions (10 mL total volume) containing triacetin (200 mM) and cellextract supernatant (prepared as described above) were run at 25° C. andat a pH between 4.5 and 10.0, using the buffers and bufferconcentrations listed in Table 5. The concentration of extract totalprotein (with or without heat-treatment to denature and precipitate E.coli-derived protein) was chosen to produce an ca. 50 mM decrease intriacetin concentration over 30 min (typically from 0.025 mg/mL to 0.40mg/mL of total extract protein, dependent on the perhydrolase). Acontrol reaction for each reaction condition was run to determine theconcentration of triacetin hydrolyzed in the absence of added extractprotein. Samples (100 μL) were removed at predetermined times andimmediately added to 297 μL of dd H₂O and 3 μL of 6N HCL. The resultingsolution was mixed, then filtered using a 30,000 NMWL filter (Millipore)using a microcentrifuge for 2 min at 12,000 rpm. An aliquot of thefiltrate (100 μL) was added to 150 μL of 0.417 mM N,N-diethylmeta-toluamide (external standard) in acetonitrile, and the resultingsolution analyzed for triacetin by HPLC using a Supelco Discovery C8column (25 cm×4.0 mm, 5 um; Supelco #59353-U40) and an isocratic mobilephase of 40% acetonitrile/60% distilled water at a flow rate of 1mL/min. Triacetin was measured by UV detection at 225 nm. The dependenceof specific activity on pH for each perhydrolase is listed in Table 6.

TABLE 5 Buffer and buffer concentration employed for determination ofdependence of CE-7 esterase/perhydrolase specific activity on pH. pHBuffer Buffer Concentration (M) 5.0 sodium acetate 0.15 5.5 sodiumacetate 0.15 6.0 sodium citrate 0.15 6.5 sodium citrate 0.15 7.0potassium phosphate 0.15 7.5 potassium phosphate 0.15 8.0 potassiumphosphate 0.20 8.5 Tris(hydroxymethyl)aminomethane 0.20 9.0Tris(hydroxymethyl)aminomethane 0.20 9.5 glycine 0.20 10.0 glycine 0.20

TABLE 6 Dependence of specific activity (mmol triacetin/min/mg totalextract protein) on pH for hydrolysis of triacetin by perhydrolasesexpressed in E. coli KLP18 transformants using 200 mM triacetin and0.050-0.40 mg/mL of cell extract total protein (ND = not determined).specific activity (mmol triacetin/min/mg total extract protein) BacillusThermotoga Bacillus subtilis Thermotoga maritima Bacillus subtilisATCC ® Bacillus. pH neapolitana MSB8 pumilus BE1010 31954 ™licheniformis. 10.0 0 ND ND ND 0 ND 9.5 12.0 21.6 71.1 ND 193 ND 9.012.5 57.1 80.4 ND 239 ND 8.5 11.3 38.8 72.4 ND 217 ND 8.0 5.8 28.7 53.9ND 221 ND 7.5 5.3 19.8 33.7 61.0 205 62.4 7.0 3.3 16.0 30.5 37.7 12056.3 6.5 1.7 10.3 11.6 18.6 78.0 23.8 6.0 0.4 4.3 4.2 7.4 24.0 12.3 5.50 1.4 3.5 0 17.6 4.7 5.0 ND 1.8 7.6 ND 4.5 ND 0.5

EXAMPLE 12 Control of Peracetic Acid Production by Thermotoganeapolitana Perhydrolase Using Buffer Concentration

A cell extract of an E. coli transformant expressing perhydrolase fromThermotoga neapolitana (KLP18/pSW196) was prepared by passing asuspension of cell paste (20 wt % wet cell weight) in 0,05 M potassiumphosphate buffer (pH 7.0) containing dithiothreitol (1 mM) twice througha French press having a working pressure of 16,000 psi (˜110 MPa). Thecrude extract was then centrifuged at 20,000×g to remove cellulardebris, producing a clarified cell extract that was assayed for totalsoluble protein (Bicinchoninic Acid Kit for Protein Determination, SigmaAldrich catalog #BCA1-KT). The clarified extract was heated for 20 minat 75° C., followed immediately by cooling in an ice/water bath. Theresulting mixture was centrifuged to remove precipitated protein, andthe supernatant collected and assayed for total soluble protein asbefore. SDS-PAGE of the supernatant indicated that the perhydrolase wasat least 90% pure. The supernatant was frozen in dry ice and stored at−80° C.

Reactions (10 mL total volume) containing triacetin, hydrogen peroxideand heat-treated, centrifuged cell extract supernatant (prepared asdescribed above) were run at 25° C. using sodium bicarbonate bufferconcentrations listed in Tables 7 and 8. A control reaction for eachreaction condition was run to determine the concentration of peraceticacid produced by chemical perhydrolysis of triacetin by hydrogenperoxide in the absence of added extract protein. Determination of theconcentration of peracetic acid in the reaction mixtures was performedaccording to the method described by Karst et al., supra. Aliquots(0.040 mL) of the reaction mixture were removed at predetermined timesand mixed with 0.960 mL of 5 mM phosphoric acid in water; adjustment ofthe pH of the diluted sample to less than pH 4 immediately terminatedthe reaction. The resulting solution was filtered using an ULTRAFREE®MC-filter unit (30,000 Normal Molecular Weight Limit (NMWL), Milliporecat #UFC3LKT 00) by centrifugation for 2 min at 12,000 rpm. An aliquot(0.100 mL) of the resulting filtrate was transferred to 1.5-mL screw capHPLC vial (Agilent Technologies, Palo Alto, Calif.; #5182-0715)containing 0.300 mL of deionized water, then 0.100 mL of 20 mM MTS(methyl-p-tolyl-sulfide) in acetonitrile was added, the vials capped,and the contents briefly mixed prior to a 10 min incubation at ca. 25°C. in the absence of light. To each vial was then added 0.400 mL ofacetonitrile and 0.100 mL of a solution of triphenylphosphine (TPP, 40mM) in acetonitrile, the vials re-capped, and the resulting solutionmixed and incubated at ca. 25° C. for 30 min in the absence of light. Toeach vial was then added 0.100 mL of 10 mM N,N-diethyl-m-toluamide(DEET; HPLC external standard) and the resulting solution analyzed byHPLC as described below.

HPLC Method:

Supelco Discovery C8 column (10-cm×4.0-mm, 5 μm) (cat. #569422-U)w/precolumn Supelco Supelguard Discovery C8 (Sigma-Aldrich;cat#59590-U); 10 microliter injection volume; gradient method with CH₃CN(Sigma-Aldrich; #270717) and deionized water at 1.0 mL/min and ambienttemperature:

Time (min:sec) (% CH₃CN) 0:00 40 3:00 40 3:10 100 4:00 100 4:10 40 7:00(stop) 40The peracetic acid concentrations produced in 1 min, 5 min and 30 minwhen using either 250 mM or 100 mM hydrogen peroxide are listed in Table7 and Table 8, respectively.

TABLE 7 Dependence of peracetic acid (PAA) concentration onconcentration of bicarbonate buffer when using 100 mM triacetin, 250 mMhydrogen peroxide and 50 μg/mL of E. coli KLP18/pSW196 heat-treatedextract total protein containing Thermotoga neapolitana perhydrolase.heated extract NaHCO₃ PAA PAA PAA total protein buffer initial (ppm),pH, (ppm), pH, (ppm), pH, (μg protein/mL) (mM) pH 1 min 1 min 5 min 5min 30 min 30 min 0 25 8.1 139 8.0 385 7.5 610 7.2 50 25 8.1 1037 6.82655 6.0 3503 5.8 0 10 7.5 88 7.5 206 7.5 453 7.0 50 10 7.0 1042 7.02334 5.5 2384 5.0 0 5.0 6.5 84 6.5 163 6.5 296 6.0 50 5.0 6.5 866 6.51894 5.5 1931 5.0 0 2.5 6.5 48 5.5 129 5.5 210 5.5 50 2.5 6.5 718 5.51242 5.0 1179 5.0 0 1.0 6.0 15 6.0 115 6.0 194 5.5 50 1.0 6.0 511 5.0610 5.0 608 5.0 0 0 5.0 41 5.0 63 5.0 79 5.0 50 0 5.0 161 5.0 152 5.0180 5.0

TABLE 8 Dependence of peracetic acid (PAA) concentration onconcentration of bicarbonate buffer when using 100 mM triacetin, 100 mMhydrogen peroxide and 50 μg/mL of E. coli KLP18/pSW196 heat-treatedextract total protein containing Thermotoga neapolitana perhydrolase.heated extract NaHCO₃ PAA PAA PAA total protein buffer initial (ppm),pH, (ppm), pH, (ppm), pH, (μg protein/mL) (mM) pH 1 min 1 min 5 min 5min 30 min 30 min 0 25 8.1 74 8.0 220 7.8 383 7.5 50 25 8.1 497 7.5 13196.5 2095 6.0 0 10 8.1 55 7.5 122 7.0 226 7.0 50 10 8.1 418 6.2 1035 6.01633 5.3 0 5.0 6.5 36 6.5 119 6.5 126 6.0 50 5.0 6.5 377 6.0 955 5.5 9895.0 0 2.5 6.5 20 6.3 33 6.0 73 6.0 50 2.5 6.5 291 5.5 510 5.3 488 5.0 01.0 6.0 2 6.0 15 5.8 103 5.5 50 1.0 6.0 167 5.0 152 5.0 176 5.0 0 0 5.00 5.0 15 5.0 31 5.0 50 0 5.0 0 5.0 29 5.0 11 5.0

EXAMPLE 13 Control of Peracetic Acid Production by Thermotoga maritimaMSB8 Perhydrolase Using Buffer Concentration

A cell extract of a transformant expressing perhydrolase from Thermotogamaritima MSB8 (KLP18/pSW207) was prepared by passing a suspension ofcell paste (20 wt % wet cell weight) in 0.05 M potassium phosphatebuffer (pH 7.0) containing dithiothreitol (1 mM) twice through a Frenchpress having a working pressure of 16,000 psi (˜110 MPa). The crudeextract was then centrifuged at 20,000×g to remove cellular debris,producing a clarified cell extract that was assayed for total solubleprotein (Bicinchoninic Acid Kit for Protein Determination, Sigma Aldrichcatalog #BCA1-KT). The clarified extract was heated for 20 min at 75°C., followed immediately by cooling in an ice/water bath. The resultingmixture was centrifuged to remove precipitated protein, and thesupernatant collected and assayed for total soluble protein as before.SDS-PAGE of the supernatant indicated that the perhydrolase was at least85-90% pure. The supernatant was frozen in dry ice and stored at −80° C.

Reactions (2 mL total volume) containing triacetin, hydrogen peroxideand heat-treated, centrifuged cell extract supernatant (prepared asdescribed above) were run at 25° C. using sodium bicarbonate bufferconcentrations listed in Tables 9 and 10. A control reaction for eachreaction condition was run to determine the concentration of peraceticacid produced by chemical perhydrolysis of triacetin by hydrogenperoxide in the absence of added extract protein. Determination of theconcentration of peracetic acid in the reaction mixtures was performedaccording to the method described by Karst et al., supra. The peraceticacid concentrations produced in 1 min, 5 min and 30 min using either 250mM or 100 mM hydrogen peroxide are listed in Table 9 and Table 10.

TABLE 9 Dependence of peracetic acid (PAA) concentration onconcentrations of bicarbonate buffer when using 100 mM triacetin, 250 mMhydrogen peroxide and 50 μg/mL of E. coli KLP18/pSW207 heat-treatedextract total protein containing Thermotoga maritima MSB8 perhydrolase.heated extract NaHCO₃ PAA PAA PAA total protein buffer initial (ppm),pH, (ppm), pH, (ppm), pH, (μg protein/mL) (mM) pH 1 min 1 min 5 min 5min 30 min 30 min 0 25 8.1 144 8.0 324 8.0 759 7.2 50 25 8.1 848 7.02342 6.5 3251 6.0 0 10 7.5 182 7.0 194 7.0 454 6.5 50 10 7.0 804 6.31951 5.5 2698 5.0 0 5.0 6.5 84 6.5 163 6.5 296 6.0 50 5.0 6.5 735 6.01825 5.7 2222 5.0 0 2.5 6.5 48 5.5 129 5.5 210 5.5 50 2.5 6.5 817 5.51758 5.3 1748 5.0 0 1.0 6.0 15 6.0 115 6.0 194 5.5 50 1.0 6.0 690 5.0980 5.0 981 5.0 0 0 5.0 0 5.0 75 5.0 63 5.0 50 0 5.0 233 5.0 290 5.0 2895.0

TABLE 10 Dependence of peracetic acid (PAA) concentration onconcentrations of bicarbonate buffer when using 100 mM triacetin, 100 mMhydrogen peroxide and 50 μg/mL of E. coli KLP18/pSW207 heat-treatedextract total protein containing Thermotoga maritima MSB8 perhydrolase.heated extract NaHCO₃ PAA PAA PAA total protein, buffer initial (ppm),pH, (ppm), pH, (ppm), pH, μg protein/mL (mM) pH 1 min 1 min 5 min 5 min30 min 30 min 0 25 8.1 95 8.0 223 8.0 456 7.5 50 25 8.1 465 7.5 1369 6.82217 6.0 0 10 8.1 73 7.5 138 7.5 222 7.0 50 10 8.1 407 6.5 1075 6.0 17635.3 0 5.0 6.5 41 6.5 83 6.5 174 6.0 50 5.0 6.5 330 6.0 972 5.7 1323 5.00 2.5 6.5 20 6.3 33 6.0 73 6.0 50 2.5 6.5 319 5.7 755 5.3 710 5.0 0 1.06.0 2 6.0 15 5.8 103 5.5 50 1.0 6.0 238 5.0 388 5.0 361 5.0 0 0 5.0 125.0 16 5.0 31 5.0 50 0 5.0 125 5.0 121 5.0 105 5.0

EXAMPLE 14 Control of Peracetic Acid Production by Thermotoga maritimaMSB8 Perhydrolase by Selection of Buffer, Reactant and PerhydrolaseConcentrations

Reactions (10 mL total volume) containing triacetin (100 mM), hydrogenperoxide (100 mM or 250 mM) and heat-treated, centrifuged cell extractsupernatant (35 to 100 μg total heat-treated extract protein/mL,prepared as described in Example 13) prepared from an E. colitransformant expressing perhydrolase from Thermotoga maritima MSB8(KLP18/pSW207) in sodium citrate (50 mM, pH 6.5) buffer, or in sodiumbicarbonate buffer (1 mM to 5 mM, initial pH as indicated in Table 12),or in water without added buffer were run at 25° C. A control reactionfor each reaction condition was run to determine the concentration ofperacetic acid produced by chemical perhydrolysis of triacetin byhydrogen peroxide in the absence of added extract protein. Determinationof the concentration of peracetic acid in the reaction mixtures wasperformed according to the method described by Karst et al., supra. Theperacetic acid concentration produced at predetermined reaction times islisted in Table 11, and the corresponding reaction pH at each reactiontime is listed in Table 12.

TABLE 11 Dependence of peracetic acid (PAA) concentration over time onbuffer, perhydrolase and hydrogen peroxide concentrations when reactingtriacetin (100 mM) and hydrogen peroxide (100 mM or 250 mM) in thepresence or absence of perhydrolase from E. coli KLP18/pSW207heat-treated extract total protein containing Thermotoga maritima MSB8perhydrolase. total PAA PAA PAA PAA PAA H₂O₂ protein (ppm), (ppm),(ppm), (ppm), (ppm), buffer, conc. (mM) (μg/mL) 1 min 5 min 30 min 2 h18 h citrate, 50 mM 100 0 155 0 0 119 522 citrate, 50 mM 100 50 409 8922001 2254 1937 bicarbonate, 5 mM 100 0 64 115 269 369 419 bicarbonate, 5mM 100 50 410 1088 1496 1423 1419 bicarbonate, 1 mM 250 0 0 22 229 280258 bicarbonate, 1 mM 250 50 624 1060 1090 1063 1021 bicarbonate, 1 mM250 0 18 105 236 275 149 bicarbonate, 1 mM 250 35 467 1047 1041 1014 917bicarbonate, 2.5 mM 100 0 54 38 156 293 346 bicarbonate, 2.5 mM 100 50256 722 976 887 855 bicarbonate, 1 mM 100 0 28 78 141 204 164bicarbonate, 1 mM 100 75 434 494 608 673 576 bicarbonate, 1 mM 100 100449 667 643 703 613 water (no buffer) 250 0 13 71 71 33 45 water (nobuffer) 250 75 512 535 533 472 448 water (no buffer) 250 100 576 668 654618 543

TABLE 12 Dependence of reaction pH over time on buffer, perhydrolase andhydrogen peroxide concentrations when reacting triacetin (100 mM) andhydrogen peroxide (100 mM or 250 mM) in the presence or absence ofperhydrolase from E. coli KLP18/pSW207 heat-treated extract totalprotein containing Thermotoga maritima MSB8 perhydrolase (from reactionslisted in Table 11). total H₂O₂ protein initial pH, pH, pH, pH, pH,buffer, conc. (mM) (μg/mL) pH 1 min 5 min 30 min 2 h 18 h citrate, 50 mM100 0 6.5 6.5 6.5 6.5 6.5 6.5 citrate, 50 mM 100 50 6.5 6.5 6.5 6.2 6.06.0 bicarbonate, 5 mM 100 0 6.5 6.5 6.5 6.2 6.0 5.0 bicarbonate, 5 mM100 50 6.5 6.0 5.5 5.0 5.0 5.0 bicarbonate, 1 mM 250 0 6.0 6.0 6.0 5.55.0 5.0 bicarbonate, 1 mM 250 50 6.0 5.0 5.0 5.0 5.0 5.0 bicarbonate, 1mM 250 0 6.0 6.0 6.0 5.5 5.0 5.0 bicarbonate, 1 mM 250 35 6.0 5.5 5.05.0 5.0 5.0 bicarbonate, 2.5 mM 100 0 6.5 6.5 6.5 6.0 5.5 5.0bicarbonate, 2.5 mM 100 50 6.5 5.7 5.0 5.0 5.0 5.0 bicarbonate, 1 mM 1000 6.0 6.0 6.0 5.0 5.0 4.5 bicarbonate, 1 mM 100 75 6.0 5.0 5.0 5.0 5.04.5 bicarbonate, 1 mM 100 100 6.0 5.0 5.0 5.0 5.0 4.5 no added buffer250 0 5.0 5.0 5.0 5.0 5.0 4.5 no added buffer 250 75 5.0 5.0 5.0 5.0 5.04.5 no added buffer 250 100 5.0 5.0 5.0 5.0 5.0 4.5

EXAMPLE 15 Control of Peracetic Acid Production by Perhydrolase usingInitial Reaction pH

A cell extract of a transformant expressing perhydrolase from Bacilluspumilus PS213 (KLP18/pSW195), Thermotoga maritima MSB8 (KLP18/pSW207),Thermotoga neapolitana (KLP18/pSW196), or Bacillus subtilis ATCC® 31954™(KLP18/pSW194) was prepared by passing a suspension of cell paste (20 wt% wet cell weight) in 0.05 M potassium phosphate buffer (pH 7.0)containing dithiothreitol (1 mM) twice through a French press having aworking pressure of 16,000 psi (110 MPa). The crude extract was thencentrifuged at 20,000×g to remove cellular debris, producing a clarifiedcell extract that was assayed for total soluble protein (BicinchoninicAcid Kit for Protein Determination, Sigma Aldrich catalog #BCA1-KT). Thesupernatant was frozen in dry ice and stored at −80° C.,

Reactions (10 mL total volume) containing triacetin, hydrogen peroxideand centrifuged cell extract supernatant (prepared as described above)in 50 mM sodium citrate buffer (initial pH 7.2 or 6.5) were run at 25°C. A control reaction for each reaction condition was run to determinethe concentration of peracetic acid produced by chemical perhydrolysisof triacetin by hydrogen peroxide in the absence of added extractprotein (data not shown). Determination of the concentration ofperacetic acid in the reaction mixtures was performed according to themethod described by Karst et at, supra. The peracetic acidconcentrations produced in 1 min, 5 min and 30 min are listed in Table13.

TABLE 13 Dependence of peracetic acid (PAA) concentration on initialreaction pH in sodium citrate buffer (50 mM, initial pH of 7.2 or 6.5)at 25° C. using 0.050 mg/mL of extract total protein from E. coliKLP18/pSW195 (Bacillus pumilus PS213 perhydrolase), E. coli KLP18/pSW207(Thermotoga maritima MSB8 perhydrolase), E. coli KLP18/pSW196(Thermotoga neapolitana perhydrolase), or E. coli KLP18/pSW194 (Bacillussubtilis ATCC ® 31954 ™ perhydrolase). PAA, PAA, PAA, initial triacetinH₂O₂ 1 min 5 min 30 min perhydrolase pH (mM) (mM) (ppm) (ppm) (ppm) B.pumilus PS213 7.2 100 250 465 1170 2525 B. pumilus PS213 6.5 100 250 281652 1984 B. pumilus PS213 7.2 100 100 160 322 1010 B. pumilus PS213 6.5100 100 170 310 830 T. neapolitana 7.2 100 250 1790 2860 3820 T.neapolitana 6.5 100 250 434 1260 2016 T. neapolitana 7.2 100 100 7981748 2500 T. neapolitana 6.5 100 100 221 607 1925 T. maritima MSB8 7.2100 250 635 1725 3565 T. maritima MSB8 6.5 100 250 95 742 2446 T.maritima MSB8 7.2 100 100 210 610 1995 T. maritima MSB8 6.5 100 100 53279 1540 B. subtilis 7.2 100 250 2430 2820 4400 ATCC 31954 B. subtilis6.5 100 250 1725 2570 3712 ATCC 31954 B. subtilis 7.2 100 100 1040 12402395 ATCC 31954 B. subtilis 6.5 100 100 691 1286 1880 ATCC 31954

1. A process for producing a target concentration of peroxycarboxylicacid comprising: a. selecting a set of reaction components to produce atarget concentration of peroxycarboxylic acid, said reaction componentscomprising: 1) at least one: i) ester having the structure[X]_(m)R₅ wherein X is an ester group of the formula R₆C(O)O R₆ is a C1to C7 linear, branched or cyclic hydrocarbyl moiety, optionallysubstituted with hydroxyl groups or C1 to C4 alkoxy groups, wherein R₆optionally comprises one or more ether linkages when R₆ is C2 to C7; R₅is a C1 to C6 linear, branched, or cyclic hydrocarbyl moiety optionallysubstituted with hydroxyl groups; wherein each carbon atom in R₅individually comprises no more than one hydroxyl group or no more thanone ester group; wherein R₅ optionally comprises one or more etherlinkages; m is an integer from 1 to the number of carbon atoms in R₅;said ester having a solubility in water of at least 5 parts per millionat 25° C.; or ii) glyceride having the structure

wherein R₁ is C1 to C7 straight chain or branched chain alkyl optionallysubstituted with an hydroxyl or a C1 to C4 alkoxy group and R₃ and R₄are individually H or R₁C(O); or iii) acetylated monosaccharide,acetylated disaccharide, or acetylated polysaccharide; or mixturesthereof; 2) a source of peroxygen; 3) an enzyme catalyst havingperhydrolysis activity, wherein said enzyme catalyst comprises an enzymehaving a CE-7 signature motif that aligns with a reference sequence SEQID NO: 2 using CLUSTALW, said signature motif comprising: i) an RGQmotif at amino acid positions 118-120 of SEQ ID NO:2; ii) a GXSQG motifat amino acid positions 179-183 of SEQ ID NO:2; and iii) an HE motif atamino acid positions 298-299 of SEQ ID NO:2; and wherein said enzymecomprises at least 30% amino acid identity to SEQ ID NO: 2; and 4)optionally at least one buffer; and b. combining the selected set ofreaction components under aqueous reaction conditions to form a reactionmixture; whereby reaction products are formed comprisingperoxycarboxylic acid; wherein the reaction products comprisingperoxycarboxylic acid reduce the reaction mixture pH to less than about6.0 within about 1 minute to about 10 minutes of combining the reactioncomponents and produce the target concentration of peroxycarboxylicacid; wherein the reduction in the reaction mixture pH is used tocontrol the target concentration of peroxycarboxylic acid produced. 2.The process of claim 1, wherein the at least one buffer is present in aconcentration in a range from about 0.01 mM to about 200 mM.
 3. Theprocess of claim 1, wherein the reaction products reduce the reactionmixture pH to about 5.0 within about 1 minute to about 10 minutes ofcombining the reaction components.
 4. The process of claim 1, whereinthe target concentration of peroxycarboxylic acid is from about 200parts per million to about 2500 parts per million.
 5. The process ofclaim 4, wherein the target concentration of peroxycarboxylic acid isfrom about 400 parts per million to about 1200 parts per million.
 6. Theprocess of claim 5, wherein the target concentration of peroxycarboxylicacid is from about 400 parts per million to about 600 parts per million.7. The process of claim 1, wherein the target concentration ofperoxycarboxylic acid is achieved within about 1 to about 10 minutes ofmixing the reaction components.
 8. The process of claim 1, wherein thetarget concentration of peroxycarboxylic acid is achieved within atleast about 5 minutes of mixing the reaction components.
 9. The processof claim 8, wherein the target concentration of peroxycarboxylic acid isachieved within about 1 minutes of mixing the reaction components. 10.The process of claim 1, wherein the concentration of peroxycarboxylicacid changes, by less than about 20% of said target concentration oncethe target concentration of peroxycarboxylic acid is achieved.
 11. Theprocess of claim 1, wherein the buffer has a pKa from about 8.0 to about6.0.
 12. The process of claim 1, wherein the initial pH of the initialreaction mixture is selected from the group comprising 6.5, 7.2, 7.5,8.1, and 8.5.
 13. The process of claim 1, wherein enzyme catalyst havingperhydrolysis activity is derived from Thermotoga neapolitana.
 14. Theprocess of claim 1, wherein enzyme catalyst having perhydrolysisactivity is derived from Thermotoga maritima MSB8.
 15. The process ofclaim 1, wherein the reduction in pH reduces perhydrolase activity byabout 80% or more in 10 minutes or less after combining the reactioncomponents.
 16. The process of claim 1 wherein the enzyme catalyst is inthe form of a microbial cell, a permeabilized microbial cell, amicrobial cell extract, a partially purified enzyme, a purified enzyme,or ah immobilized form of a partially purified or purified enzyme. 17.The process of claim 1 wherein the peroxycarboxylic acid is selectedfrom the group consisting of peracetic acid, perpropionic acid,perbutyric acid, perlactic acid, perglycolic acid, permethoxyaceticacid, per-β-hydroxybutyric acid, and mixtures thereof.
 18. The processof claim 1 wherein the enzyme catalyst lacks catalase activity.
 19. Aprocess for disinfecting a hard surface or inanimate object by producinga target concentration of peroxycarboxylic acid comprising: a. selectinga set of reaction components to produce a target concentration ofperoxycarboxylic acid, said reaction components comprising: 1) at leastone: i) ester having the structure[X]_(m)R₅ wherein X is an ester group of the formula R₆C(O)O R₆ is a C1to C7 linear, branched or cyclic hydrocarbyl moiety, optionallysubstituted with hydroxyl groups or C1 to C4 alkoxy groups, wherein R₆optionally comprises one or more ether linkages when R₆ is C2 to C7; R₅is a C1 to C6 linear, branched, or cyclic hydrocarbyl moiety optionallysubstituted with hydroxyl groups; wherein each carbon atom in R₅individually comprises no more than one hydroxyl group or no more thanone ester group; wherein R₅ optionally comprises one or more etherlinkages; m is an integer from 1 to the number of carbon atoms in R₅;said ester having a solubility in water of at least 5 parts per millionat 25° C; or ii) glyceride having the structure

wherein R₁ is C1 to C7 straight chain or branched chain alkyl optionallysubstituted with an hydroxyl or a C1 to C4 alkoxy group and R₃ and R₄are individually H or R₁C(O); or iii) acetylated monosaccharide,acetylated disaccharide, or acetylated polysaccharide; or mixturesthereof; 2) a source of peroxygen; 3) an enzyme catalyst havingperhydrolysis activity, wherein said enzyme catalyst comprises an enzymehaving a CE-7 signature motif that aligns with a reference sequence SEQID NO: 2 using CLUSTALW, said signature motif comprising: i) an RGQmotif at amino acid positions 118-120 of SEQ ID NO:2; ii) a GXSQG motifat amino acid positions 179-183 of SEQ ID NO:2; and iii) an HE motif atamino acid positions 298-299 of SEQ ID NO:2; and wherein said enzymecomprises at least 30% amino acid identity to SEQ ID NO: 2; and 4)optionally at least one buffer; b. combining the selected set ofreaction components under aqueous reaction conditions to form a reactionmixture; whereby reaction products are formed comprisingperoxycarboxylic acid; wherein the reaction products comprisingperoxycarboxylic acid reduce the reaction mixture pH to less than about6.0 within about 1 minute to about 10 minutes of combining the reactioncomponents and produce the target concentration of peroxycarboxylicacid; wherein the reduction in the reaction mixture pH is used tocontrol the target concentration of peroxycarboxylic acid produced; andc. applying the peroxycarboxylic acid produced in step (b) to a hardsurface or inanimate object.
 20. The process of claim 19, wherein the atleast one buffer is present in a concentration in a range from about0.01 mM to about 200 mM.
 21. The process of claim 19, wherein thereaction products reduce the reaction mixture pH to about 5.0 withinabout 1 minute to about 10 minutes of combining the reaction components.22. The process of claim 19, wherein the target concentration ofperoxycarboxylic acid is from about 200 parts per million to about 2500parts per million.
 23. The process of claim 22, wherein the targetconcentration of peroxycarboxylic acid is from about 400 parts permillion to about 1200 parts per million.
 24. The process of claim 23,wherein the target concentration of peroxycarboxylic acid is from about400 parts per million to about 600 parts per million.
 25. The process ofclaim 19, wherein the target concentration of peroxycarboxylic acid isachieved within about 1 to about 10 minutes of mixing the reactioncomponents.
 26. The process of claim 19, wherein the targetconcentration of peroxycarboxylic acid is achieved within at least about5 minutes of mixing the reaction components.
 27. The process of claim26, wherein the target concentration of peroxycarboxylic acid isachieved within about 1 minutes of mixing the reaction components. 28.The process of claim 19, wherein the concentration of peroxycarboxylicacid changes by less than about 20% of said target concentration oncethe target concentration of peroxycarboxylic acid is achieved.
 29. Theprocess of claim 19, wherein the buffer has a pKa from about 8.0 toabout 6.0.
 30. The process of claim 1, wherein the initial pH of theinitial reaction mixture is selected from the group comprising 6.5, 7.2,7.5, 8.1, and 8.5.
 31. The process of claim 19, wherein enzyme catalysthaving perhydrolysis activity is derived from Thermotoga neapolitana.32. The process of claim 19, wherein enzyme catalyst havingperhydrolysis activity is derived from Thermotoga maritima MSB8.
 33. Theprocess of claim 19, wherein the reduction in pH reduces perhydrolaseactivity by about 80% or more in 10 minutes or less after combining thereaction components.
 34. The process of claim 1 wherein the enzymecatalyst is in the form of a microbial cell, a permeabilized microbialcell, a microbial cell extract, a partially purified enzyme, a purifiedenzyme, or an immobilized form of a partially purified or purifiedenzyme.
 35. The process of claim 19 wherein the peroxycarboxylic acid isselected from the group consisting of peracetic acid, perpropionic acid,perbutyric acid, perlactic acid, perglycolic acid, permethoxyaceticacid, per-β-hydroxybutyric acid, and mixtures thereof.
 36. The processof claim 19 wherein the enzyme catalyst lacks catalase activity.